Energy Cycle has been "optimized" for Series X/S and is currently available for preorder at the low cost of Free. It's been suggested that the free price is only for those who have the Xbox One version of this, so keep that in mind.
Well damn. Didn’t think anything could get me to go back for more of that, but the price is right.
Also confirming the free price only for those who owned the last-Gen version of it. When I pulled up the page, it was only $.60 off, but then once the page refreshed after I logged in, it went down to Free.