Before the 2020 pandemic struck, there were neither homeschooling, nor online lessons, and all the learning for school age children was done in Präsenzunterricht (classroom teaching). Hence, there was no need for this term.
Now we need this term to differentiate between online lessons and classroom lessons.
Language does evolve around the change of times.
Ab sofort wieder Präsenzunterricht! (From now on again classroom teaching!)
Well, this could also mean the virtual classroom (in the global world), but not to most Germans. 😉