> but are the manufacturers going to provide firmware updates for 10 years?
Typically, yes, at least for severe, headline-generating issues. Most others tend to be able to be worked around in Linux kernel drivers anyway (and usually better than by most vendors…), so realistically the burden will be on Google to use a 10-year LTS kernel and meaningfully support it receiving backports for various issues.
> Are Intel or Mediatek going to be providing 10 years of microcode updates for the CPUs used on these devices?
Intel at least seems to be providing updates for 7+ years, going by their recent microcode releases. It's not quite as out of the ordinary as it seems, at least for the big vendors. Mediatek is another question.
Typically, yes, at least for severe, headline-generating issues. Most others tend to be able to be worked around in Linux kernel drivers anyway (and usually better than by most vendors…), so realistically the burden will be on Google to use a 10-year LTS kernel and meaningfully support it receiving backports for various issues.
> Are Intel or Mediatek going to be providing 10 years of microcode updates for the CPUs used on these devices?
Intel at least seems to be providing updates for 7+ years, going by their recent microcode releases. It's not quite as out of the ordinary as it seems, at least for the big vendors. Mediatek is another question.