If people believed that this is the end of PoW the prices of GPUs would already be going down, because people would know that they have at most 7 months of run (until end of Q2) and that they'd be massive selling of graphic cards. I don't see it happening which means that either:

* miners don't believe the switch is happening that soon

* miners know they'll keep PoW with some other blockchain

* miners are gambling hoping that they'll still make profit

Maybe all 3?