I have a customer that is voluntarily escrowing for flood insurance and has it in place. Have received a map revision notice and a new SFHD. Do I have to provide a notice to the customer and what should it say?

I'm not sure. The map revision shows they moved into a SFHA and they were previous not in one???

if they are now in a flood zone and weren't before (doubtful because you said they have flood insurance) but anyway, then you would have to provide the stand flood notice, and allow 45 days for them to acquire insurance.
If they are coming out of a flood zone, then no. But I would certainly send a congratulations letter!