I expect it to be modern console only, maybe even not for PS5, but for the rumored PS5+ and high end PCs.
It'll be on PlayStation 5 and Xbox Series X|S for sure. For PC, NetherRealm doesn't handle the PC ports, and
Mortal Kombat 11 was actually far easier on the requirements than
Mortal Kombat X was (since a more skilled company handled it's port). A mid-range PC will likely run the game without issue and still look great.
As for a new PlayStation rumours, at best it'll likely be a "slim" version, if even. The cost vs performance of silicon hasn't drastically changed, so releasing a mid-gen refresh right now makes 0 sense, especially considering this generation still hasn't properly taken off.
Digital Foundry expects there will be no mid-gen refresh this generation, and at best we'll get "slim" versions later in the generational life cycle. Time will tell, of course.