Evidence suggests otherwise though. EA made an even stronger claim about Ninty and wiiu and completely abandoned development for it because of low sales. Simple as that. Rockstar said they would make a ps3 exclusive, Agent, a game we never heard about ever since they made the announcement. Countless companies have been cancelling games or dropping support over the decades. They never give an excuse and when they do it's either a good one, i.e. low sales, or a lame on (Tomb Raider apparently can only be done on XBONE). There is no reason to believe that Ubisoft is any different and their past actions have shown nothing to suggest that they care about providing an excuse which is not going to convince anyone anyway. They had more than enough examples to justify dropping support anyway. 

The whole conspiracy theory is incredibly silly to me. If you have a theory, at least show (you, the OP, or anyone else) a pattern. Has Ubisoft done the same with psvita recently? Did they do it with psp or wii? What exactly are you basing something that makes zero business sense on?

It's not a conspiracy theory, and I'm also not saying that this did happen.  I am just saying that there is some business sense that could be made out of it, even if it isn't a very strong one.  You're claiming zero, but it's not zero.  That's the point.