I agree the pinnacle weapons were a mistake but only because they were legendaries instead of exotics. Compared to a bulk of the exotics in the game they have similar abilities. What breaks the weapons is the fact that they are Legendaries allowing you to pair them with exotics or other pinnacle weapons.
The only restriction is whether to run a specific exotic in its place but then the other two slots could still be other pinnacle weapons.
I’d honestly be fine with making them automatic exotics in Shadowkeep as they will still likely be the best weapons in the game and to make new general legendaries competitive the power creep would be a disaster.
Not the worst idea, but some weapons would definitely need a buff to be worthy of Exotic. I really like Revoker and I'm actually excited to get Hush, having looked more into it (I'm a sucker for high skill-gap weapons), but I'd never use either of them as an Exotic in their current state. Then again, there are many current Exotics that aren't worth using either.