Not sure if I would call it clever. Crypto will always leak the amount of data if you don't pad or ensure a constant data rate. Its also far from the first time compression has lead to a side channel. For instance https://en.m.wikipedia.org/wiki/CRIME

-edit- Even durning world war you if you were listening on enemy radio commucations and they had not been decrypted you could tell if the enemy was planning somthing by noticing a large increase in radio communication. This a long known issue if you dont pad your data and send it at a constant stream. You may leak some information.