Little late but thought I’d share my experience…
I was also looking for a alphard hybrid. Assumed that as it was a hybrid, it would be ulez compliant.
Did find a potential alphard and was actually on the point of transferring money for the purchase when my partner asked the seller if it was ULEZ compliant. Seller evaded the question…
When we checked on TfL, it said it wasn’t. Seller suggested we misrepresent the reg number so the ‘o’ looked like a ‘zero’, so that a non existent car would be searched which would therefore be compliant….
Anyhow, we scarpered.
We did also find another seller who was really helpful and upfront about his cars and could provide all the specs and details. He also said reg 56 onwards hybrids are ulez compliant. Would recommend him if ever you consider getting the hybrid again.