They probably mean cost efficiency rather than thermodynamic efficiency. It would cost a lot to install those systems in addition to the electricity storage necessary to run during a blizzard. I’m not disagreeing that electric is better but there’s a lot more to consider than just “modern systems are better so you should install them” and it’s not a lie to say so.

At very low temperatures? I think if you're above zero F, you should be ok, but below zero it gets expensive.

They're not talking about taxing gas - they're talking about banning it.

I wouldn't say it's "completely false", it depends on the temperature. Heat pump efficiency drops as the temperature drops. If you live in a place with very cold temperatures for prolonged periods of time, gas may indeed be more efficient.

... gas heating is more cost efficient (heat per currency) is probably what he meant.