They would split that McKee, top comes off, and chisel, cut, scoop, dig, out all the old style foam. Then refill it with closed cell. A good shop can do it quickly if they aren't already backlogged with work.
No foam has a real long life expectancy. It literally starts breaking down the minute it cures. It will shrink, powder up, and yes, even today absorb water after it has a little age on it.
The problem foams have stems from the owner of the foam, or better yet, the owner of the boat that the foam resides in.
Until people start realizing that a boat is no different than a car, tractor, or a box end wrench, and if you put a roof over it it'll last a long time.
Boats sitting in yards including tarped boats...have much shorter life spans than garage kept or sheltered boats.
But the main problem is people using the logic that boats are made for water so they are made to get wet. It's the wrong logic.
Once again DR hit that one on the head. The 2 worst things you can do to a boat is let it sit, and store it in the open. Covered can actually be worse it done improperly with the wrong kind of tarp, or placement.