We are a next day availability bank and I've noticed that in some of our older branches the funds availability signs at the teller line don't have the line about funds from electronic direct deposits being available on the day we receive the deposit. All the other verbiage is there about the first business day, second business day, etc. but not the electronic deposit part. Is that line mandatory?

You need to have the more expansive version posted somewhere that the average consumer passes on the way to make a deposit. The versions at the window can be a bit more abbreviated.

I would not suggest doing any significant overhaul of any of your lobby Reg CC notices now. There are changes going into effect 7/1/2020 that may cause updates, and there's whispers suggesting there might be more of an overhaul effective then (although I've seen no real evidence of same).

Our bank will be celebrating Juneteenth on Friday, June 19th and closing our branches at Noon. Should we post a sign at the ATM stating all deposits made after 12:00pm will be made available on Monday, June 22nd. Or, is signage at the branch door sufficient?
A taped sign relating to funds availability at the ATM could be removed.