possibly
I've known about this for years (especially stuff like meditation and anatomy starting at 0 for most creatures, and going up), but I haven't noticed any creature with skills over 100 gain any in their 100+ skills from it. Then again, those skills are hard to gain in, anyway, and Magery in particular may run into the end of the skill gain window, since creatures can't cast 8th circle spells. Resist Spells, Eval Int, Wrestling and Tactics might require training against something with similar skill range, and keeping one GD from killing another long enough for the wild one to get skill gains, even if possible, might be problematic.
Any Dev want to comment if it's even possible?