[Sciolist]

There're two types of cashouts - creditback and overcredits. Creditbacks are where the initial deposit is effectively cancelled - it's returned immediately, but only applies to some deposit methods. Overcredits are only made when all creditbacks have been used (i.e, you don't have deposits that can be cancelled).

eChecks can only do overcredits, so if you have creditbacks available still from other deposit methods, the system will process those first.

As for who is eligible, I don't know the criterea used (and probably wouldn't be able to tell you if I did), but these things are typically rolled out over a small proportion of the player base first, incase anything goes wrong.