Apple never donated computers to schools.A quick google search will give you the "kids can't wait" program. This program allowed donated computers to go to 9000 California schools.
The others may have been discounted, sure, but they did donate and it still means that Google is just following in the footsteps of those before them.
I'll also note that $100 off of a current computer isn't as bad as it sounds, considering the low starting price of a good-enough-for-internet-and-school machine. I had green letters on a black screen back in the 80s, giving way to not-so-refined pixel art a few years later, all for a computer that cost more than they do now before you even adjust for inflation. Computers simply aren't the same sort of cost they were back then (they still cost, but the machinery isn't as big of an expense)