Meier has also always been very streaky. I'm not sure whether it was last year or two years ago, but he basically couldn't buy a goal for an extended stretch and then went on an absolute tear. Making blanket statements about a player because of a handful of playoff games is pointless.
Production in sports is incredibly random in small sample sizes (especially hockey) and it gets magnified and blown way out of proportion in the playoffs. There are a million examples, like how Arod "sucked" in the playoffs until he single handedly won the Yankees the world series in 2009. Or how Mitch Marner was getting run out of Toronto because of a couple playoff performances, until he put up 8 points in 7 games last year and has 10 points in 4 games this year.
Meier is a great player and he'll be fine over the long term. It's a 4 game sample.