Ours is an Ultimate as well. Initially, they said officially May 2023 but likely pre Christmas. Coming in a few months early is quite a bonus.
I believe it is because the cars are fully loaded with no extras, so they can churn them out in just in colour variants. It was the same a few years ago with the Mazda 3’s I got for my other children – a special offer for the top spec models, no extras and a choice of dark grey or black. Simple!
Motability should take note and do a deal with the brands to reduce the combinations (e.g. 12 models of the Arona) of models with very little difference between them to get a better price.