[2022] No more than 1 battleship and 2 Superships - what does this mean?

Correct!

Correct to the last part: 1x bb + 6x (cruiser + dd), and any 2 of those can be super

That's correct.
The last two seasons restricted teams from bringing more than 1 of any ship. That restriction has been removed.

Yamagiri may just surprise you.

It kinda does everything the smoke / torp DD's want to do but can also gunboat a bit with Shima detect, 3 more torps tubes, burst-fire from 4.5s Shima guns, and 4.5k more health.
Smaland will be king for a long time, but Yamagiri has a LOT of utility that didn't previously exist.

I wouldn't suggest it normally but I did see a number of Hurricane teams this season make decent use of Shima and Somers. While I still think a Gunboat like Rag is better, Kleb will be missing and I suspect that might just be enough to make Yamagiri's utility work