First time I've heard of Q-Up fares on Delta!
My guess is that Flying Blue rigidly sticks to the "miles awarded are for the fare class you purchased, regardless of whether you travel in a higher class" rule.
Particularly as AF and KL have no such equivalent program, so they would just look at this as an upgrade for which you didn't really pay - i.e. you paid Q, but got F (only because it was available at the time of booking), even if sanctioned by Delta and even if Delta would correspondingly give you an F credit.