The previous 30fps cap will be removed by default in menus and cinematics, but in Krypt mode you'll have to toggle it on yourself—and the dev team says it's "only recommended on high-end configurations".
Yesterday's patch also included fixes for crashes on launch. Judging by the comments underneath the patch notes, some players are still experiencing crashes, and NetherRealm said it's "working on other similar issues, so we will keep updating the game with fixes for users who report their crashes to us".
Some players are seeing bugs in the new 60fps mode, such as mouth animations not working properly when a character talks. Hopefully NetherRealm will be able to address those problems soon.
In case you missed it, Matt's Mortal Kombat 11 review is here.