They will wreck Arduino, for sure. But it will not do anything to to AVR or PIC.
Rising prices on classic boards will not accomplish anything. There is simply no money that would be meaningful to Qualcomm that you can extract from Arduino selling legacy boards.
RPi can increase prices, but even them can only do that so much. There is minimal, but still competition out there. I personally use Orange PI for SBCs. They are cheaper, and in many ways better.
But for Arduino there are dozens of compatible boards. Any price increase will simply move more people toward them. The only thing they can do is make IDE harder to access (hide behind subscription or even registration).
They clearly want to push their new hardware, but they are going about it in a really weird way, which is destined to fail. I would expect this whole UNO Q board to fizzle out.