1. There's no need to recalibrate the compass after a firmware update.
2. The facility to calibrate the compass is still in the app settings.
It's just been moved deeper down because too many people thought they were seeing an instruction to recalibrate in the checklist when it was just a button you could use to recalibrate.
While I wouldn't rule out anything as being a possibility, bricking is certainly not the norm. Most people who think it is have never bricked a Phantom themselves. They are just repeating problems they've seen on the Internets.