No it isn’t, I spoke to Motability when my Enyaq orders AP dropped £1100 on Oct 1st, absolutely no problem at all, they rang my dealer to make sure it was sorted out. Doesn’t affect you dealers commission or the order placed with the factory at all. It’s only the amount the dealer collects on behalf of Motability (which they then transfer to them).
I’ve emailed my delaer as the AP has dropped a further £400 this quarter. My dealer isn’t great but if they mess me about I’ll phone Motability again.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!