I mean, what do they expect? People already have their Chromebooks, they're set for a decade, it's not like power or utilities with recurring revenue ...
Not really, the normal support life is 6.5 years from first manufacture, I've seen chrome devices for sale with less than 2 years support remaining.
Albeit not as many as they needed at the start of the pandemic.
They'll most likely reuse them for many years, OR have a student keep a single chromebook through many grades. Schools in the US aren't that well funded that they can give every student a free laptop every year.
At most, you might issue returned ones to people who lost or broke the one they were issued.