1. Injured Reserve - and by extension, Long-Term Injured Reserve - ceases to exist when the regular season ends, because there's no limit on the size of the Active Roster in the playoffs. Thus, every player who's on IR or LTIR comes off at the end of the regular season whether they're healthy or not.
2.
Vegas didn't make the playoffs in 2022. Meaning, Stone being "activated from LTIR" - which again, is a function of how IR works - didn't do squat for Vegas for the postseason. Which, you'd know if you read the thread or just took a look at the end-of-season standings on your favorite website that has such information.