I think the high rejection rate is down to a combination of low personal research by motability customers and very favourable return conditions (compared to private lease contracts).
Whilst MG may not have value EVs compared to their offerings from previous years I think, in general, there are still some very good EV deals on MB and as quotas continue to exist, even if they are softened, MB will still be a useful outlet. I’m certainly not considering returning to ICE come my next renewal.