Despite its reputation as the game that everyone loves but doesn't play, in 2023 King of Fighters XIII finally received the much anticipated update in the form of Global Match edition, which included new lobbies and rollback netcode.
Unlike many other updates of this kind, this was done by Safari Games, rather than Code Mystics, which led to some mixed feedback regarding the quality of rollback and the stability of online lobbies.
Hard to say if this was improved for the PC release, but SNK already confirmed that the original version of King of Fighters XIII will be delisted from Steam on January 23rd, and it will be replaced shortly after by the Global Match edition on 20th of February.
Keep in mind that this is a separate entry and not a free update. If there's any consolation, SNK has also confirmed that those who already own King of Fighters XIII will have a special discount, reducing the game's price to $6.99/€6.89.
You can currently wishlist the game on Steam, but the pre-order is not yet available.