Well I believe so too because I have a NRT-ORD flight next week and I've been regularly monitoring seat availability on the availability tool.

3 weeks before the flight the availability was something like
Y9 B9 M9 H9 Q9 V2 W0

then around 2 weeks before the flight it was something like
Y2 B0 M0 H0 Q0 V0 W0

7 days before it was
Y9 B9 M2 H2 Q0 V0 W0

today it's
Y9 B9 M9 H9 Q9 V9 W9

So I believe they're playing on the availability, maybe targetting people who'd make up their mind about 2 weeks prior to the flight and suggest only Y is available?

It will probably be a rather full flight and I'm in E+. I hope I won't have anyone sitting next to me. And I'm crossing my fingers so that my connection at ORD will go well...