Adams isn't guaranteed any future money at this point.
Dead money for money previously paid normally doesn't come into the decision-making process. The money has to be accounted for at some point anyway. It only becomes an issue if acceleration of the future cap hit is significantly more than the forthcoming salary/bonus costs and the team is in cap trouble. That isn't the case here. Adams has a post 2023 dead money/cap hit of $14.22M, whilst the cost of retaining him for 2023 is $11M. Teams can move other cap expenditure around over a 2-3 year period so a $3M+ difference over a $410M+ or $630M+ budget is small potatoes. Again, it's not an actual $14.22M cost, it's merely when money already spent is accounted for.
The cost of retaining Adams for 2023 is $11M, (plus performance incentives). $2.56M of that figure becomes fully guaranteed 5 days after the Super Bowl. Realistically the Seahawks ought to make a decision before that guarantee kicks in.
Personally I don't think Adams is worth $11M to the Seahawks, or on the open market, so the 'purely business' decision would be to release him. Offering him reduced terms is an option.