well before this classes, tank use to have flame thrower. and blaster has the same hp as the tank.
But tanks lacked any long range weapons like the rocket launcher. Also, minigun is essentially the flamethrower without the DoT effect. It doesn’t really make sense to take away the flamethrower from the class that is essentially named for it though. Both classes have weapons that are suited to their roles and I doubt that they will be changed (with the exception of balancing them).