It would be totally self-defeating of Zwift to come up with all these new incentives for people to level up and then switch them off when you need them. Even Zwift aren't that stupid. (Famous last words)
I think you're over estimating Zwift's shoot oneself in the foot policy

Introduce steering, then allow it to be disabled.

Its exactly the same in real world racing, more aero bike/helmet, wheels, dropper posts, skinsuits, the advantages shouldn't be blocked.