It will change, you'll see.
The "but they're captains" argument isn't worth anything in my opinion. The other supernovas were also captains, and Law and Kid are already below Zoro in strength (and I would dare say in portrayal).
Luffy hardcarried them to 3B, he won't carry them further.
I agree.
1. It will change because from that moment on, Zoro is the WSS. His WSS status will supercede his other status.
So if Zoro becomes WSS, Zoro having on the same level as "the new generation Emperor" like Law & Kidd is normal.
2. It will elevate and affirm Luffy as PK. PK is someone higher than Emperor.
So, again, if Luffy becomes PK, Zoro having on the same level as "the new generation Emperor" like Law & Kidd is also normal.