Still waiting for this game to be 100% content complete to buy it at one low price, but I'm looking forward to eventually playing it with these skins
Modern fighting games like this are slowly morphing into full GaaS / live service games. They will probably continue releasing new skins like this for the game even after it's fully fleshed out.
Case in point, the "Ultimate Edition" just released for next-gen consoles and includes the Aftermath DLC along with the first two season passes.
This product entitles you to download both the digital PS4™ version and the digital PS5™ version of this game. The definitive MK11 experience Take control of Earthrealms protectors in the games TWO critically acclaimed, time-bending Story Campaigns as they race to stop Kronika from rewinding...
store.playstation.com
And yet, even if you buy that $60 "ultimate edition" game, you'll still be missing these skins. And about a dozen other cosmetic skin packs like these:
Three new character skins. Celebrate a bloody Halloween with the All Hallows Eve Skin Pack. Play as Beast Within Johnny Cage, Bad Medicine DVorah and Blizzard King Sub-Zero.
store.playstation.com
The Eternal Klash Skin Pack is entitled to owners of the Mortal Kombat 11 Aftermath PlayStation™Store pre-order but can also be purchased in-game with in-game currency. Three new character skins. The Eternal Klash Skin Pack includes Unbound Rage Scorpion, inspired by MK9; Son of Arctika...
store.playstation.com
Three new character skins. The Klassic Femme Fatale Skin Pack outfits Mortal Kombat 11 characters in Klassic, MK3 inspired costumes and includes Sole Survivor Kitana, Outworld Courtier Jade and Old Blood Skarlet.
store.playstation.com
They'll probably be releasing a new skin pack every month or so, but I doubt they'll ever roll it into a full retail package. Then comes the inevitable Mortal Kombat 12 release and the cycle starts anew.