This is where the intentional ambiguity and conflating come into play by Canucks fans.
Obviously J.T. Miller got 99 points last season. So you can call him a 100 point player in the literal sense that he achieved such an accomplishment last season. However, does he do that again simply because he just did it last season? That's a different discussion and looking at the input from Canucks fans on their own board, many of them think he won't repeat his career high and thus, want to try to capitalize while he's at his greatest.
Most GMs don't seem to view him as a 100 point player in the sense that you can rely on him to replicate that, otherwise the interest should've been greater, both in terms of quantity of teams wanting him and in terms of quality when regarding what they'd pay.
He got 100 points last season, but many Canucks fans and apparently GMs don't see him as a player that, majority of the time, will be that kind of player. Especially moving forward.
Calling him a 100 point player is disingenuous if you're trying to advertise him as a guy who's likely to continue to be that guy. Otherwise, that accomplishment means nothing to teams who are only concerned with what he'll do for them in the future.