Because the commissioners broke some rules, got banned from the discord, and had their alien Priveleges taken away.

And they will not come back

Once you've been banned, you can't commission anything.

Which transformations were deleted?

As I know list includes: haloiator, big brain, glow in the shark, blockhead, invicibull and heavyweight.

I remember the first 4 but I had no idea of the last 2

It's Blokkhed and Big Brain