In a complete vacuum would I swap Edvinsson for Hughes? Sure, you would be dumb not to. But there are so many other considerations that go into this. The trade wasn't a one for one swap, there was a lot of value in addition to Buium in Rossi and a first round pick going the other way. Edvinsson is 4 years younger and is a restricted free agent after this season, with a projected long term deal at 7 years $7,700,000 per that I've seen. Hughes wouldn't commit to a long term contract (or couldn't? I never really looked into it) and he's a free agent after next season looking at a $12-14 million per year or more extension. So you're risking a guy walking for nothing, and if you do get him signed it is going to be at a significant cost of your cap space.
Edvinsson has shown he works incredibly well with Seider on the top pair. He seems to be well liked by his teammates and coaching staff. I feel like I see him getting better and he seems to work hard. I am more than fine betting on his situation here. Especially when the Wings would still need to go out and get defensive help for the third pair imo. Swapping Hughes in for Edvinsson isn't going to completely alleviate that this season even if you force feed minutes to Hughes.
And it isn't like suddenly the Wild are some unstoppable juggernaut with Hughes as they've gone 11-5-5 so just a game over .500 counting wins and losses. Somehow got spanked by the Devils and Jets back to back. So I reject the notion that this is the only way to navigate the current successful season.