Just add something so the progression won't just halt and won't matter anymore. They added this progression and for it to not matter anymore after reaching max level does not seem rewarding.
It's like having a progression system to reach the left 4 Dead style at the end. If you add a progression system, make sure you keep progressing and feel part of the core design and not just filler.
I was really hoping that you can still level up guns and classes after you have maxed them for end game purposes. Because after every match those weapons XP gain at the end does not make sense and feels useless once you maxed all your guns up.
Why not add prestige levels after you hit the max like in the Division and add a very miniscule amount of increase, or maybe add cosmetics for guns and unlock them after every prestige for your collection. Just add something so leveling up weapons is still viable in end game, (Some people will say, What endgame?) exactly....