Long lead times are nothing new for example in 2018 when I lasted renewed my car, I was told, would take 5 months to deliver because of WLTP, that changed to 9 months so I cancelled the order.
This seems to be getting a bit regular these days and you would think that Motability would changed the ordering time scale of 3 months to something a bit longer, but no, they won’t.
I’ve heard of some folk who do a deal with dealer for orders longer than the 3 months but its unofficial and if the dealer sales the car before your 3 month order date becomes concrete there’s nothing you can do about it.