Of course, Texas, Louisiana, et al, will add 100 miles more or so of land as the Gulf of Mexico recedes (the water is locked up in the glaciers).
Imagine Galveston 100 miles inland. Lots of very productive cropland possible on what used to be ocean bottom.
That’s a good point, when we get deep into the next ice age a lot of continental shelf will be land again. Many of us think there’s going to be some good archeology done in the future on the shelf around the world.