Players will be able to use tablet computers in the dugout to watch previous plate appearances in 2021. Video was banned after the Astros sign stealing scandal and the Covid pandemic limiting people in the video room:

It was a jarring change for some hitters during a down year for offense during the pandemic-shortened season. But Major League Baseball has cleared the way for the return of in-game video on dugout iPads beginning on Opening Day, with catcher signals obscured by a computer program.

ESPN.com

That sounds like a good solution to the problem.