After reading what Raycroft said and listening to Chris and Dom yesterday explaining why the Bruins got the return they did for Ullmark, I think there are two ways at looking at this deal.
If we isolate this deal from a pure value standpoint, I still don't think the Bruins got enough in return for taking on Korpisalo's contract. I think if there was another B/C-level prospect or pick added to the deal from Ottawa, it would have been a fairer return especially since the Bruins are making a divisional team stronger by giving them Ullmark. The Bruins in this deal also did not free up enough cap space which makes you wonder if there were any other deals available that would have cleared all of Ullmark's cap hit. Does this also mean that the Bruins would be fine with waiving Bussi and potentially losing him if Korpisalo beats him out at camp?
If you look at the trade at a larger picture, the Bruins got a 1st, a younger Maroon replacement, and a backup goaltender for a goalie they basicallly got for free in free agency in 2021. The remaining goaltenders in free agency aren't the greatest and don't espouse the greatest of confidence. Korpisalo may have been the best choice to battle it out with Bussi for that backup spot on the NHL roster. Korpisalo can always get waived if Bussi beats him out.
If the Bruins keep their 1st and the player they draft becomes an NHLer, if Korpisalo bounces back and could potentially be moved at the trade deadline* for another asset or in a package that returns a player with a higher cap hit, and if Kastelic becomes a fixture in the bottom 6, then this trade could end up well in the long run.
That's the Catch-22. That's a lot of ifs, and it will all depend on what the Bruins do at the draft, free agency, and the rest of the offseason.