You’re trying to solve a hypothetical problem in the future at the expense of todays team. Teams don’t say “hey we should trade our best defenseman today because possibly in the future we might have cap issues” (which is impossible to know without knowing where the cap is going to be in 3/4/5 years time, especially considering there’s likely to be a new cba between now and then, and that’s not even taking into account things like player injuries and ltir)
It’s a stupid idea for a team hoping to contend today. You’re getting Ceci, Graves, Gudas level players for 4-4.5M and even if you ponied up to get someone in Nurses range with a cap hit in the 4.5 range chances are you are going to have to pay that person in the next 3-5 years likely 6-7M+ on a long term deal so there goes all the hypothetical long term structural cap relief.
Every year Nurses deal becomes less of a percentage of the cap and less of a burden. The guy is 28, he’s not falling off a cliff any time soon. What you’re suggesting would be idiotic for the Oilers, it would be terrible asset management.