The multi-crew guys thing is a delayed reaction; I think you'll see it in the guys dropping letters post-DH ticking up.
Not being current due to having to take boat orders can force a lot of guys hands into a 2 year set of orders that'll put them at 13-14 when they walk. Not quite as bad a dead zone as the 15-16 year guys as far as the airlines are concerned, but still a tough thing to walk out on after 13 years with not much to show for it.
The alternative is to drop your letter as soon as you check into the boat, go to a regional or contract ISR gig asap, get current, and keep updating that app. The paycut alone might persuade guys to suck up the DH pain just to keep the bills paid while earning a few hundred flight hours the hard way, but I think a lot are going to keep walking as soon as they think they can get hired with whatever they've got in their logbook.