Yes
We intend to put two of each of the new RSA and ECDSA keys into rotation in the next few months. Two of each will be ready to swap in at a future date, and one of each will be held in reserve in case of an emergency. Read more about the strategy in our December 2023 post on the Community Forum.
swap in -> swapped with the current active set. I don't think there's much benefit to increase the number of active signers, but they do want the rotation.
AFAIK, the current randomization is a temporary thing anyway. LE engineers shared an idea (privately) some time ago that in the future, each DC will have local certificates that are not shared between DCs. Thus, the load balancer effectively decides what intermediate you're getting, but the DC itself doesn't randomize. Adding more randomization into the mix doesn't align that well with that idea.