itsjustmejonhotmailcom said: " In practice, those unions (collectively COBUG, the coalition of broadway unions and guilds) have granted nearly identical terms to non-league producers. But in the case of someone like Rudin, if he tries to produce a show as a non-signatory, I'd imagine the terms COBUGwould demand would be untenable which could make it moredifficult for him to return."
Deadline's article on the potential ramifications concurs.
https://deadline.com/2021/04/scott-rudin-broadway-league-confirm-resignation-ramifications-theater-landscape-immense-1234742961/
"Without League membership, Rudin would be something akin to a non-union producer, or at least a producer without the across-the-board agreements that the League negotiates with numerous theatrical unions and guilds. Technically and theoretically, Rudin could, in fact, negotiate his own separate agreements with Actors’ Equity Association, the American Federation of Musicians and more than a dozen other theater unions, but the task would be onerous and is very seldom attempted: For years, Disney Theatricals took the non-League route, but had an entire department at its disposal for negotiations and deal-making.
Add to that, both Equity and American Federation of Musicians Local 802, along with SAG-AFTRA, issued a statement recently condemning workplace harassment, and though the statement didn’t name Rudin specifically, the timing left no doubt. Equity in particular has been loudly urging the League to address the Rudin situation.
...
While the exact implications for Rudin’s current productions – major critical and/or commercial successes including To Kill a Mockingbird, The Book of Mormon, West Side Story and the yet-to-open The Music Man starring Hugh Jackman and Sutton Foster – are unclear, it’s most likely that the union agreements already in place – negotiated by the League – will stand, allowing the shows to go on. Rudin’s future endeavors are murkier. The ripple effects of today’s most unusual, perhaps unprecedented, development remain to be seen."