Damn. Torn Achilles and torn ACL, the two nightmare (used to be career ending) injuries for athletes, to two of Golden State's best players. Probably the worst luck I've heard a team go through, in terms of severity of injuries, the players it happened to (both being star players), the short span they occurred in (occurring in consecutive games), and it happening in the finals of all places.
Makes sense how Klay was able to seemingly move fine for a bit afterwards, though. Have read and heard about people who have gone through the same injury, feeling fine, not thinking much of it initially, before being told they've torn their ACL.
KD should be ready for playoffs. Same for Klay. Even without them they should be able to reach playoffs comfortably.
Next season is gonna be interesting though (this one was too). If Lakers get AD, they are gonna be strong. If Raptors keep Kawhi they are gonna be strong. Buks are gonna be strong, as will be Dubs. Rockets probably will be good too.
Don't think the Warriors without KD and Klay (given they stay) will make the playoffs comfortably. They'll likely be a lower seed if they do. The West is tough. As you said, Lakers will probably strengthen, with there being a good chance they take up a playoff spot next season, as well as other borderline playoff teams who will also make pushes.