I doubt Brendan intended for you to stop using Mozilla Firefox to avenge his resignation, which he did voluntarily against the wishes of the board.
In fact, I suspect Brendan voluntarily resigned in order to LIMIT the damage he was causing to Mozilla's reputation and user base, which he cares about.
So I'd guess he's probably not happy about social injustice warriors boycotting Mozilla on his behalf.
Again, I encourage you to seek clarity instead of spreading misinformation: Why don't you ask him?