If the legal case offered an existential threat is it not likely they would? Maybe that over exaggerates our worst case scenario.
You can argue it both ways, but there is a bit more to it either way.
There is so much work and time that would have gone into it to even get it to that stage (when the charges came out). By that point, you have commited time and money with multiple consultants, professionals, teams of people, timeframes, funders, brokers, potential end users etc.
Projects get shelved a lot of the time, but it is most often more expensive to do that and re-start later. Plus when you do, costs and timeframes shift, regulations change, and it becomes unpredictable.
I think people also look at it purely as a 300m 'footballing' project, because it is part of the stand. But it is more than that and there are three or four component parts not reliant on the stadium itself. The hotel (the biggest in manchester, when complete), the multiple f&b outlets, the retail, and possibly offices, will pay for themselves. As investments, in that location, with the co-op arena just finished. So the only thing you are then potentially questioning against any doom outcome, is build the stand or not. And as they are so complexly interlinked, it is almost impossible to separate them. Might as well commit to the whole lot come what may.
That's how I see it. It is reassuring, to an extent, that the club have kept going with it and not shown any hesitation. But given the accrued momentum on it, for something of this scale, the claim that it is 'proof' of complete confidence, is a bit basic. But it does imo go the opposite way however, i.e had it been paused, with the implications and costs that carries, I would almost certainly read that as the club being concerned.
For me the club's own statement, and the progress on the pitch, is all the proof of confidence I need, fwiw.