bb:
Anchorseal does 3 useful things that I know of - But we use it primarily for the reason you state - to keep green timber from drying too fast.
The second thing is that it softens wood, especially end grain, making it easier to work. For example, smoothing off the bottom of a post with a slick, or widening the end of a mortise with a chisel. We do that intentionally once in a while, especially on reclaimed timbers, which are really hard and brittle. But usually, it's on a surface that we sealed anyway, for reason #1.
The third thing is that joinery that's been sealed (for reason #1) slides together really nice! Like greasing the skids. This is really just a happy side effect - we wouldn't do it just for that reason - we do it for reason #1.
