That may be true, to an extent, but i doubt it. What about all the guys running hackers? duos? Most of which seem to be totally fine. I'd say its a marketing gimmick used for a company to try to sell their motors along with their ESCs. Who knows though, maybe a certain ESC is optimised to a certain motor... But with brushed you never saw a company that advised running a certain brand of motor, did you?

What's any different with brushless?