I'd be amazed if there wasn't some clause that saw Sepalla / SISU get some sort of return if certain things happened, that would be pretty standard wouldn't it? You wouldn't leave yourself open to selling the business and 6 months later the business is £100m+ better off.
Could well be the same with players. Otherwise what's the benefit to not holding on to the next transfer window, selling everyone who attracts a fee and taking that money out of the club?
But I wouldn't read too much into them being a Wembley. Would just be a courtesy to invite the owners who were, like it or not, involved in part of the season. If they start turning up at games regularly next season then maybe its time to worry.