I thought the restrictions on selling tickets are part of the deed and not short term. If correct you’d need Mt Snow (aka Vail aka the Evil Empire) to agree. Doubtful.
I am not a lawyer, nor pretend to have any substantial knowledge of contract and/or real estate law outside of having signed some mortgage papers a few times over the years ;)
I wouldn't be surprised, if at some point, if legally pressed on this topic, that since there have been so many transferences of owners since that initial clause was written in with the ASC sale, that not unlike the lifetime passes at Killington and Wildcat became null and void with the transfer of ownership, that this clause may not have any remaining legal grounds remaining.
The question then would be, do the new owners/presumed new(returning) members if the club does indeed reopen, WANT outside day ticket usage?
That may be an entirely different question...