I went back to my local dealer today. They have had a '21 white RT with ACC that I've been tempted by, but I thought I really wanted blue. Well, today they had received a blue bike (no ACC and reserved for someone else) and it turns out I don't like the color as much in person (it's darker than I expected). After staring at them side by side for a while I decided to go with the white one rather than putting a deposit on another blue one they have in transit. So
@Mellow is right that there are bikes out there.
I also heard from the dealer that they've done a bunch of research on this topic. They delivered a bike to a seemingly very annoyed customer and that put their parts guy on the project of figuring out if a retrofit is possible. The parts guy seems sharp and he swears that it is possible and he has figured out all of the parts, some of which will not become available until late January. So
@MasterSpin77 there may be hope yet. I'll be back in there at least once in the coming days (to pick up my bike!), so let me know if you want me to try to get that parts list. I should probably get it and share it here as a resource for others.
Side note: the financing on 2021 bikes is 1.9% and on 2022 it's 4.9%. I was waffling on whether to finance or not at 4.9%, but at 1.9% it's a no-brainer. So that was a nice little bonus.