Whether Barzal plays center or wing is always a complicated issue - it was even when he played center.
At first playing with Horvat, Barzal was sort of playing as a pure winger, but he kind of broke out of it last year, as they became more comfortable trading roles. Part of that is that Barzal has become a really effective defensive player, combining it with his top notch ability on breakouts. The only times they don't trade roles is on faceoffs.
So in some ways, he's more of a center than he was (he'll often be low in the defensive zone while Horvat has point), but in other ways less (he doesn't take faceoffs).
This has always been the weird thing with Barzal when it comes to people questioning whether he's a "True Center" or "Winger". To me, the premise of having him shift to the wing in order to take away some measure of "defensive responsibility" ultimately kind of neuters the thing that Barzal is phenomenally good at. ie. Transition play, clearing the neutral zone and entering the offensive zone with speed, puck control, and an abundance of creative playmaking vision and passing skills to create all sorts of different opportunities for linemates. To me, that's always been served best by playing him as the "center" where he's afforded more opportunities to wind up and really show off that puck-carrying capability with less of a "stop-start" game that you tend to get on the wing.
The only real thing holding him back from being a "center" to me, is his lackluster faceoff ability. Which...is an issue, but a fairly minor one. You can have another guy on his line take draws if it's just too catastrophic, especially on the Powerplay where you want Barzal starting more on the perimeter as more of a "quarterback" anyway. It's also something that...he may never be great at it, but faceoff strategy and just relentlessly working on it, is a technical skill where you can often see improvements, up to at least breaking even or whatever.
Anyway...as for the specific trade proposal here, i'd wager that is indeed a pretty competitive offer for Barzal. I think it looks a lot more realistic than a lot of what a handful of teams repeatedly want to throw NYIs way in exchange for him.
I think if it were Vancouver trying to bring him home, it'd probably look something like 1st (Top-15), Lekkerimaki, B Prospect. Which is probably in the same general ballpark...but the Minny offer probably wins out if the Isles are looking to "retool" a bit more quickly. Vancouver offer might win out if Isles are a bit scared about what that new Rossi contract is going to look like, and the significantly smaller "cap savings" that might represent. I think these are the sort of pieces that it'd probably take though...given how many teams out there are desperate for a reasonably young Top-6 Center right now, and how few are even potentially available.