Based on the music in the trailer, SMS Power Strike II will be emulated at the correct 50 Hz speed. Hurrah!
This is Japan only for the moment but it'd surprise me if it didn't get a UK/EU release due to Power Strike II's cult status.
Confirmed for Switch and PS4, Japan release at xmas. It also looks like there's a Game Gear Mini which includes the games, for anyone with thumbs impossibly tiny enough to make a teeny Game Gear viable!