Problem with this, is that if the OP’s base had decayed, that would be traceable in his event log. I’m sure if that was the case he wouldnt still be wondering what happened. Similiar to a purge or if something had been kited over to destroy stuff all of that appears in the event log, as certain structure break it will say the others lost stability.
It is entriely possible that as OP and others suspect that the update caused some kind of roll back or data loss or asset corruption which resulted in the base not still being saved on the servers drive anymore. These things happen in many other games and is why I call it almost an act of “nature” it’s something even the best devs can’t always forsee, it doesnt mean they can’t help out players who fall victim to this though. Funcoms hands off approach to in game customer service is really not tasteful in my opinion. I get it they deem they don’t have the resources but in all honesty, for a game like this that is prone to so many of these kinds of issues, having no support team to assist players with this is fairly ridiculous, I would argue there are other areas that budgets can be cut to make space for this service. It really isn’t winning them any popularity contests.