It's well beyond the scope of this thread to go too deep and any discussion will get shut down by fanboy nonsense, like above, if they deem their precious gamepass is being attacked. Which is actually not the case with that tweet, at least not in the way the usual will automatically think anyway.
But I will say it's a lot like how MS handle the teams they buy, there's a lot of clauses and promises and a lot of misunderstanding and failures. The Gamepass isn't the problem, it's more how new the whole thing is to the industry and how it HAS to evolve as it can't stay this way for long.
And contrary to the belief of some, it's not about MS and their deep pockets at all. They, like all other businesses, will be (and are which is one of the issues here) clawing back from other areas. As I said, more will come out from both sides (devs/MS) over time and it'll hopefully lead to a more standardised practice. Though at what cost to the consumer will be the question. It's all well and good paying a tenner a month (or a quid of course) for ok to occasional decent games now, but if the quality is to improve and the developers/publishers are happy with the cut, then that cannot and will not last. Then we shall see what people are happy with, as let's face it if you aren't buying games and relying on the GP then you won't have much choice but to pay what is required.