They said they can't make a zac skin with clothes at the moment because there are many many problems with the rigging and how the clothes on him would act when he turned into a giant ball for his ult or a puddle from his jump
tl;dr: they cant put clothes on zac bc it screws with the rigging as his anatomy and body changes with his diff abilities
Sounds like his rigging could use some serious work then, for future skins.
and his blobs could be like, corsages :D