What development of x1 your talking about? They where a year late and $100 more. That at launch is garbage.
They were a year late and $100 more expensive with the purpose just to have the more powerful system this generation. (interview with Phil Spencer confirming 2016 scorpio)
It's not likely they'd spend extra cash in R&D and sacrifice a year of sales for the lolz.
I expect the same mindset next generation. If I had to put money on a company having the more powerful system, it would be MS.
I'm still not convinced either way though. Simply too early to call.