Do people have any faith in the these sorts of notices, when nothing ever produced by the company has yet been supported that long?
When a chip is supplied by a vendor and needs to be supported in the kernel, the whole thing can be EoLed by one stubborn vendor. That's one of the promises of Fuchsia - decoupling hardware support from the rest of the system, so you can keep everything else up-to-date even if Qualcomm tells you to kick rocks.