Rocco Landesman, National Endowment for the Arts chairman, speaks during the American Advocates For The Arts House Appropriations Committee Hearing. (Kris Connor/Getty Images/GETTY IMAGES)

This promised to be a fascinating weekend at Arena Stage, where 30 leading lights of the American theater world were gathering — playwrights, Broadway producers, leaders of nonprofit companies, directors, government arts officials — to put heads together over one of the thorniest problems bedeviling the stage: how to invigorate the birthing of new plays.

Robert Brustein, the critic and former artistic director at theaters at Yale and Harvard, was to be on a panel with Arena co-founder Zelda Fichandler. Rocco Landesman, National Endowment for the Arts chairman, was sitting down with Gregory Mosher, the Tony-nominated director and onetime artistic head of Lincoln Center Theater. As Arena detailed it all in a press release, the conversations Friday and Saturday were also to include Oskar Eustis, producer of New York’s Joseph Papp Public Theater; David Hawkanson, managing director of Steppenwolf Theatre in Chicago; Kevin McCollum, who with two partners brought “Rent” to Broadway, and dramatists such as Amy Freed, author of Arena’s forthcoming comedy, “You, Nero.”

I would love to have been able to report on the quality of all of these exchanges, on the dynamic in Arena’s handsomely refurbished rooms, as some very smart people wrestled with an issue unequivocally central to the creative health of American drama. For it is in substantial measure the strength of the relationship between the nation’s nonprofit theaters — the heavy water-carriers of new-play development in this country — and the commercial sector that will determine in the broadest sense how much reach and impact original plays and their authors will have on the culture.

Yes, it would have been enlightening, for it was not simply the elite stakeholders given seats at Arena’s table who had a vested interest in how this conversation evolves. True lovers of the performing arts know that, as much as it’s consoling to feel the powerful resonances of old works, the true measure of a nation’s artistic vitality is what the art-makers are creating right now. And so what the opinion leaders at this unusual “convening” were hashing out was of paramount interest to the rest of us.

But for reasons that remain opaque, Arena decided to close all of the conference to the public with the promise that the company would, in time, publish a “white paper” summarizing its contents. (It hired theater academic Diane Ragsdale, whose theater blog “Jumper” appears on the influential Web site to write up the conference.) And as a result, I think, a rare opportunity was squandered to bring this important colloquy fully into the light.

This is a critical moment for talking about new plays. The local excitement over new work has ratcheted up, thanks in part to the new playwright residency program at Arena; the ongoing commissions of new musicals at Signature Theatre and the establishment of an original-works project at Studio Theatre.

The phenomenon is replicated in other cities. “The money is filtering down and the plays are filtering up,” says Jason Loewith, executive director of the District-based National New Play Network, which helps initiate the unveiling of new plays by multiple companies across the country in what are known as “rolling premieres.”

It is in the nonprofit theaters across the country, and their allied institutions in New York, that the vast majority of plays are born. Over the past decade, in fact, every play and musical that won the Pulitzer Prize for drama began life at a nonprofit theater — and virtually all of them went on to a commercial life on Broadway. The commercial sector has made itself an ever more integral part of the development of new shows, chiefly by providing financial assistance to productions in the form of “enhancement money” to nonprofit companies, funds that in some cases amount to enhancements in the millions.

With so much on the line — and with the accompanying concerns about how such partnerships affect a company’s status as being “nonprofit” — the decision to place the conference behind a curtain seems particularly ill-timed. Arena officials say that although their past “convening” on this topic was open in part to the public, this one barred both the media and general public so that the discussions could be as frank as possible. (One top official told me that some invitees would only participate on the condition that the conference be closed.)

Certainly, Arena and its artistic leadership — Artistic Director Molly Smith and her second-in-command, David Dower — deserve heaps of credit for their commitment to bringing the industry together in this worthy endeavor. Frankness is a commendable goal, too, but you’re left to wonder what could be uttered on the topic that wasn’t suited for general consumption?

Put aside the all-access-pass eternally hungered for by the media and even the burgeoning, society-wide trend for institutional transparency in an expanding array of previously sequestered events. It’s worth noting that Arena, through its Theater 101 program, even allows its audiences regularly to sit in on that once scrupulously off-limits process, play rehearsal. (And in what feels like further irony, I was invited to be part of a public discussion later this month at Arena, called “Theater Beyond Twitter,” focusing on the expanding influence of social media in theater circles.)

But the most disappointing aspect of denying spectator status to others in the field may be that it sends an unfortunate message of exclusivity to the constituency that cares about this issue most of all: the emerging generation of playwrights and theater-company managers who desperately need to feel the encouragement of those in higher places. The 1 percent in that room are required with opportunities such as this one to fling open the doors to the other 99.