Training and studying is blocked in any guild when being in any temporary
form. I'm not going to explain why, because it would probably require more
research. My guess is that the training is blocked for technical reasons and
temporary forms could modify some values which might somehow affect training
costs/maximums/something which we want to avoid. So praying and recognition by
Tzarakk is completely separate issue and not related to spawn
training/studying.

The polymorphed races have been blocked from training because they might have
different skillcosts and skillmaxes than the original race, thus making it a
good decision to actually polymorph to train every time.

So the reasons for this are more technical than an issue with roleplaying. But
I'm sure Darol can come up with a nice made up story to back it up from the
"realism" perspective.