Also you use the phrase prematurely leaked, but a finalised agreement had been made as of 31 July then negotiations were reopened after the AGM was called and a date set for the vote to open, which all sides agree was done at Estrella's behest. Regardless of the rights and wrongs of Estrella feeling it was necessary to do so in light of the change in the club's financial position, that's why there wasn't a finalised agreement to share. The email containing the agreement as it stood was sent only 2 days before the AGM, with a later email saying agreement had been reached on the outstanding clauses coming less than 2 hours before it started.
If the email with the IA as it stood is what Estrella are arguing has been a breach of the NDA by MCT and so is a basis for legal action, would it have been appropriate to wait another two days to share it? How would any MCT members have had a chance to properly scrutinise it and discuss it at the AGM if that was the case and we all only had an hour and 45 minutes to read and understand a 30 page (discounting the 20 odd pages that just listed existing shareholders) legal document? For that matter, if the MCT board sharing the IA with the MCT membership was a breach of the NDA and Estrella have cause for legal redress as a result, was briefing individual MCT members about the progress of negotiations not itself a breach of the NDA as well then, before even getting to the content of the statement?
You can of course argue that they shouldn't have shared the legal advice regarding the veto and argument of majority control along with the agreement and instead kept that back for the meeting or otherwise communicated it separately, but I'd also say not sharing the legal advice the MCT board received from their lawyers with the membership whenever there's something beyond 'all good, nothing to see here' about the deal with members would itself have been an unacceptable lack of transparency.
We've had contradictory statements of fact made about the course of events by all sides here, with all claiming they have a paper trail as evidence to support their version of events. None of that evidence has been shared with the membership to allow a concrete "this person is indisputably lying about this and this person is indisputably telling the truth" conclusion with evidence backing it up to be known among the membership. We now find that one of the parties is threatening the other with legal action over breaking non-disclosure agreements.
You can interpret that many ways: one side did fuck up and the other side therefore has a right to take legal action against the other knowing they'd win, both sides or neither breached the agreement and a legal threat is a bluff, or in the same scenario a legal threat is not a bluff but they'd lose. Maybe a majority of the MCT board feel they're bang to rights and have no choice but to avert legal action because they'd lose, maybe a majority simply think it's the right thing to do because they want the Estrella deal back on track regardless, or maybe a majority don't think they're in the wrong but legal action isn't a risk worth taking because it would be more time and money diverted away from saving the club. Whatever the case may be, a cynic could certainly conclude though that threatening legal action over the NDA is ensuring that those paper trails which provide evidence of who was telling the truth at the AGM will never see the light of day.