Well, their last statement on Twitter says that everything is supposedly fine, the work continues, and the fact that dev sold his tokens is only for the best.
I have not to think this as a way to resolve the declining situation but this only means that this particular project is soon to be dead and likely just an exit scam. A project that won't have market support will usually be ending up like this. Investors never see this SUSHI have potentials and so it is likely they are are just ignored.
Well, I hope their continuous work will be true and not just to make their early investors to be fooled.