Except it does violate the policy.
or otherwise require some form of monetary compensation to download or access an add-on.
Forcing people to view ads, which grants monetary value to them, is indeed profiting off addons.
I encourage everyone to email WoWUI@Blizzard.com to make sure they’re aware of what Overwolf is doing, if the forum CMs don’t address it. (At least I hope that email still works. It’s the email listed in the Addon Policy Threads)