I think it must depend on the fare bucket, and who knows what else.

I can confirm that I bought my mother an MSY-IAH ticket last month for about $200, which with the 20% discount, was ~18,000 UR points. She absolutely DID get PQDs for it. I just checked. United.com shows a total of $162 PQDs. The PQMs and PQSs posted normally as well.