That's a meaningful distinction; most hardware can keep running current software for a long time after it's theoretically EOL, but Chromebooks stop updating their software outright when the hardware falls out of support.
A disposable laptop is an absurd concept. The idea itself should feel appalling.
Maybe there's a hidden cost to pay for making e-waste disposable hardware which is felt at the environmental level.
I'm pretty disturbed at how this waste is not considered in the rich west, as it only looks at the monetary cost of the device and not at the fact that those devices most likely end up in landfills much sooner than should be accepted.
Just becasue we can financially accept such a thing, doesn't mean we should, for the sake of the environment.
Besides, after several years of use by kids, I have a hard time imagining these things becoming anything other than waste.
And where I live in the west, I pay an additional tax for products which create e-waste (namely consumer electronics) and I must dispose of them at appropriate facilities. E-waste is definitely a problem but it's not a relevant factor here as far as I can tell.
This isn't the case for Android because of the SOC blob and how entwined it is with the Linux kernel, but that reasoning doesn't apply here.
The problem I see is that school budgets don't account for such expenses on the regular, so schools end up using hardware for years and years after EOL.
Either way, seems like a good deal to me.