Agreed. Predicting WR floors are always dicey, since it's even more dependent on game script and quarterback play more than any other position. Heck, even AB, the poster boy for mega high floor and mega high ceiling put up 6.2 points in my half point PPR league.
That's probably where I'd put his floor (in my league at least). 4 for 40, which is 6 points in 0.5 PPR. I agree that he'll probably average a little more than 10 points going forward, but I think 6 is a reasonable bet for a floor for him on a bad day.
Compared to players on my roster, with his schedule coming up (HOU and NE in the playoffs is super juicy, with TN and Tampa in the mix before end of the season too), I'll likely flex him over Dez on a weekly basis (Evans and Baldwin being my other starting WRs) until Freeman comes back from injury, and even that will be a toss up for me. Just for reference for those trying to gauge his value.