Ok the plot thickens, lol. Seriously I just wanted to pass this info along.
My 2022 Vado 4.0 that I bought in March of 2022 (so very early) mastermind definitely does not have a battery in it as per the LBS mechanic (who I trust) but the "newer" mastermind does have a (non replaceable) battery. He has taken them apart before and seen both configurations.
My mastermind and remote control is being replaced. It's not under warranty anymore but my LBS says that Specialized will likely discount the part or maybe even cover it.