I'm pretty sure Tegra2 got firmware updates during its lifetime, and I know that TI do updates for OMAP.

Those updates might not make it through to consumer devices, but that used to be the case for things like GPU drivers too. Google pushed an updated SGX driver for the Galaxy Nexus with 4.1, and Apple pushes updates to their own drivers every release.

perhaps, but even so that does not mean that it won't get supported in later generations. I'm sure people said the same thing about FLAC but it is now supported in lots of devices, like those running Android.