Don’t know if I am missing something but just went on to the Motability site and there are EVs available. As you say the announcement from our “green government” may have taken the market by surprise but I can’t see any other way to go than EVs.
The prices for EVs are going down and will continue to do so. Shame we don’t get grants like Germany €9000 and France €7000 with some of the more enlightened Countries including schemes to scrap old diesel and petrol cars as well.