Such asinine bullshit lmao, no offense

Discussing tactics out of character isn't meta gaming; expecting people to have internally perfected every single strategy they might ever need to encounter and remember them eternally is beyond ridiculous. Your players are players, remember that. They are actual human beings who are playing a game in their free time.

They are not a professional wizard or rogue who knows the ins and outs of every one of his spells and abilities perfectly because it's literally their life and they have thousands of hours of extremely high-stakes (i.e. life or death) combat experience. That's their characters. When you tell your rogues player "hey, sneak around the side, I'll make a distraction", you're not telling it ingame to your rogue because you have to communicate this strategy to the rogue ingame. The rogue character and whoever's making the distraction know it's a possible strategy they can employ, again, they have probably been in countless fights. They wouldn't forget it. Exact same as player 1 telling player 2 "Hey, dont you have that spell you can cast next turn? That'd be really useful!". Player 2 characters knows he has the spell. He knows it'd be really useful.

Player 2 maybe forgot for a second, because he has a 40 hour work week as an account and plays this game once every two weeks, so expecting him to have the same battle prowess and tactical instinct as his ingame sorcerer who's a combat veteran with thousands of monsters killed is ridiculous.

And that's why your players need to communicate, and punishing them for it is just stupid.