People might not be aware how much they can save on gas prices by switching to full electric. I don’t see any downside in advertising an estimate. It’s not like they are presenting that as the price with a footnote that says it includes gas savings.
That is very close to what they are doing. If it had the real price and it said "You would save x amount with this option" I doubt anyone would care.
So, it’s not just “like” they are doing it, they are doing it.
They are allowed to advertise "price X, but remember you also save Y per year". But not "price X minus Y".