From my deduction, it hasn't changed.
It still only casts mage spells, and in fact the skree doesn't cast sleep at all, it seems to proc off of melee attacks. Or at least thats what it seems to do. If the skree can't reach a monster (swoop on a rock) it won't sleep, at least mine never did.
That being said, mine is at about 75 wrestling and I can't find out why a skree would be even 2 slots. Its far less powerful than a dread warhorse, has overall less resists, and can't be used as a mount.
The only difference is the sleep on melee attack which breaks when the skree hits things.
The magery helps out but the problem is that the skree has such low mana and low damage that usually your mana will run out before it kills most mobs.
When you look at other 4 and even 3 slot tames, the skree just doesn't add up. Even 2 slot mares/bake are arguably better pets, just because the bring similar stats/magery and can be combo'd with other pets.
When I read the description of the skreeon the main SA page, it said something about difficult to tame, but once tamed would friend anyone. I thought maybe they were a 4 slot pet that could be transfered to anyone, regardless of taming/lore levels. Tested this theory, and it didn't seem to work.