"One would assume that it’s mostly playoff teams looking at Miller and Pettersson, and why would a playoff team want to unload a core piece in-season?"
The quote I bolded in your post, and the quote above right after LeBrun said that in the article, is reason to believe Carolina is legitimately one of the few serious trade partners to get EP.
"With the season going the way it has and the drama in the room involving the players, Canucks general manager Patrik Allvin is wise to at least see what the market is for each. It doesn’t mean either will be moved, but the mere fact we know for sure the Canucks are talking to teams on each player is certainly not nothing."
Exactly what I was thinking. It's not nothing even if neither gets traded in the end. The fact that they are actually still listening (as of that article's post date of yesterday, January the 7th) on trade offers for EP says something.
Regarding the people negative about getting EP, I get the trade cost is a concern, and his salary too. At the same time, what other 1C (on most teams) could we get as our 2C that's (1) actually a legit threat offensively, (2) is very respectable defensively, and (3) is still a young player (EP is 26)? Point is, there's certainly substantial pros to trading for him, and it isn't all cons.