I will admit that POP packs are absolute hell to both research and implement and my sample is low enough I could have been caught out by a sampling error, but AFAIK no POP 1 pack can contain 2 uncommons, but I was able to roll that in the pack sim.
If you find something in my doc is wrong feel free to send it to me BTW, I'll update the sheet with any new findings I can find motivation to investigate.
EDIT: POP2 has the same issue
EDIT2: POP3 too
EDIT3: and POP4
EDIT4: and POP5
EDIT5: POP7 as well