Not to beat a dead horse, but if the objective is to “help those who have to maintain old code”, then they know what BEM is, so why would you say in the intro “I guess if you are reading this, you may not know what BEM stands for.

This article might be interesting if you talked about what BEM was trying to accomplish, why it’s no longer necessary, and why it’s now not being used. You should also recommend against the use of BEM, since I still run into people occasionally who imagine (perhaps after reading articles like yours) that it remains some kind of best practice.