We did have quite a bit of usage and awareness among schools already before the shutdowns started. Couple that with there being many options for teaching online… I wouldn't be surprised if a lot of schools just switched to having their teachers attempt to do their normal teaching via Zoom (which sounds really hard to me!). Many schools had contracts of various sorts with other online learning platforms.
Some schools or classes haven't had great follow through rates, which is unfortunate, but educators all over have had to quickly adjust. I suspect that more robust plans will be in place by the fall, given how much uncertainty there is for fall classes. Khan Academy is, at least, an always-free resource that's there for people if they need it.
That 2.5x is starting from a large base, and there's also a lot of activity in online education generally.