I think Seattle has a better pool of players to draft from, but I think they will not be able to replicate the perfect storm to go on a deep ride in their inaugural season like VGK did. I think Seattle's "floor" is higher, but their "ceiling" is lower if that makes sense.
Seattle won't have to overachieve in the inaugural year to be competitive. IIRC, VGK was considered/predicted to be barely beyond a bubble calibre team and they over achieved under Gallant (plus they rallied together after the shooting). I think Seattle will be a guaranteed bubble team from the get go. I think Seattle has a slight advantage on the cap crunch (although VGK leveraged cap decently too). VGK did great to flip extra players, it'll be interesting to see if Seattle can replicate or exceed that (especially if they retain).
Lots of extra players retired early during the pandemic and there's seemingly more quality trickling out between most teams 7-3-1 or 8-1 lists, so the quality of some players are improved (slightly less borderline non-NHL calibre players to meet requirements). There's going to be higher end players being exposed than in the VGK draft IMO, but some of them might have a shorter shelf life (more UFA quality and less RFA quality/disappointments vs VGK?). Lots of players got a huge boost playing for VGK (chip on their shoulder and miffed they were discarded). This might have been due to the short time to understand they might be exposed and thus they felt discarded. But with the longer awareness of the Seattle draft, I wonder if the likelihood of the Seattle group playing with the same level of chip on their shoulder won't be as high (the player worries, but accepts they are the piece to be exposed). I think Seattle will end up with more historical top line and top pairing players who had a drop in play vs VGK had more "disappointment players" who they hoped would grow into top pairing/top line players.
Not expansion draft: but I think another major difference is that Vegas after its inaugural season has the Vegas advantage. That's why they perhaps were able to insulate and improve their bubble core with pieces like AP and Stone (trade and extend) to solidify themselves as a legit contender from being a solid bubble team. I think players will definitely consider Seattle a nice place to play, but I doubt that interest will be like top 5 in the league like Vegas was from the get go.