Is that needed after April 1st ?? Aaron Judge played here last year for the Yanks and only he knows if he is vaccinated.
Yes it is. A few days ago there was a story from the NY Yankees manager expressing concern that their unvaxxed guys would not be able to play in Toronto. It's the same for Kyrie Irving and the Brooklyn Nets, he can't come here to play the Raptors. In the NHL so few players are unvaxxed it hasn't really been a story but it's still there.
The rules could change at any moment, but as of now those are still the rules.