Normally I think you're right, but I don't think any team would be trading for him to pay him 3 million real dollars, and have 1.2 million dead cap to play him for a month then bury him in the AHL though. They would trade for him to be the starter or backup every night.
I think it just hurts our negotiating position, although having three NHL goalies and wanting to move cap does that to a significant degree already.
Brossoit has zero value right now. In fact, because of his contract, he probably has negative value. He's coming off a very serious injury that could be career threatening. Even the last season he played was poor. The only way for Vegas to get an actual asset for Brossoit would be to waive him first and maybe retain some salary as well.
Of course Vegas could also trade Thompson or Hill but those are two good goalies who have provided the team with nothing but solid goaltending while Brossoit, at this point, is a question mark at best. Of course Vegas could keep three goalies on the roster but that's a shortterm solution at best. When has the three goalie model ever worked? I think it makes sense to waive Brossoit and go from there. Chances of him getting claimed are not very good though.
If they don't wanna risk losing Brossoit until they know more about what they've got in him an option that nobody mentioned yet would be to just send Thompson to Henderson because he's waiver exempt. That would give them time to evaluate Brossoit and they could still call up Thompson whenever they need him. Not much of a popular move but I could see Vegas go there if they're high on Brossoit...which I doubt they are...but you never know.
Either way, expect Vegas to buy time by sending Brossoit to Henderson for a conditioning stint. Brossoit will of course have to agree to that but if he doesn't he'll probably just get his ass waived.