Just a quick observation, but why do people (no one specifically but just some in general in different places) still say that Ridley's appearance, particularly with Samus Returns, is just forced or contrived fanservice? I get it's easy to call it that if you ignore context, but it still served a purpose as a prelude to Super Metroid which the end of II/Returns is just right before. I suppose after things like Phantoon in Other M (which made no sense for it to be there even though I liked the appearance), some be conditioned to think as such even for Ridley? It just seems like an odd way of discrediting him as a final boss though in the case of MSR. I mean if not him, or the Metroid Queen for the 2nd or 3rd time (4th if you count AM2R), who would they have preferred as the final boss? A new enemy wouldn't of tied in at all, and Diggernaut filled the new enemy role nicely enough as a recurring boss, so I don't know.
Secondly, there's still the argument of how Ridley needs to take a break asap or somesuch. Now, I think giving him a break during MP5 (like with MP2) or the next spinoff depending on the nature of it would be reasonable, but if MP4 is like the start of a new trilogy, then he has as much business being there as the other major appearances he's made. I don't think he'll ever reach Bowser levels of overexposure though, not that I really see people consistently say "They should give Bowser or Ganon/dorf a break" like you do with Ridley. It's just weird.