No, before the update I was definitely fragmenting 300 pots and getting clovers. So clovers do exist in frag. Or at least, they did. I have about 7 leftover clovers to prove that frag did give clovers. I was going back and forth making pots and disassembling them to train frag (one of the requirements is the frag of 300 pots).
We might be able to frag 500 pots and get clovers now, but I haven't tested that yet.