My boy came from pocket pets and is happy and healthy, vet approved.
I agree to take them to the vets and get them checked out, which you should do no matter what with new gliders.
The problem is that if they were inbred, there could be conditions wrong with them down the line that you can't control and won't show up on a vet exam right now, since it's not a problem right now. Heart problems, liver problems, etc., could happen due to improper breeding... but bare in mind that this can also happen to correctly bred animals.
I guess what I'm trying to say is, you shouldn't worry about health issues just because they're from pocket pets. There's nothing you can do to stop a disease, just like humans can't predict something like cancer. Just make sure they're healthy now and take good care of them. Gliders don't show illness much so watch them closely :)