From the video

Video: Top 100 Flex Rankings & Tiers (Week 1)
Moving over to DJ Moore. Typically DJ Moore is going to be higher than this. But the problem is it's about the toughest matchup that you could possibly ask for, right? So we do have to discount DJ Moore slightly going up against Houston.
Mentioned at 15:01 – 15:13Captured by STACKED 5 hr after posting

STACKED’s take

Positive signalMatchup

Typically higher but discounted for toughest matchup vs. Houston.

Typically ranked higher, but discounted due to facing Houston's tough defense, described as one of the toughest matchups possible. James Cook applies a slight discount to DJ Moore's ranking due to this unfavorable defensive matchup.

D.J. Moore headshotD.J. MooreWR · BUFPlayer page — value, ADP, projections, and every insight