I'm going to assume that you are broadly happy with doing all the meal planning and cooking as if you're not, that's a different conversation. But I would absolutely 100% take him at his word - if he doesn't care, then don't worry about whether the food is perfect or reheats well for him.
Things we do on nights like this where everyone is at different points - I had a thread about it too -
Tacos - the shells can be heated in the airfryer in 2 minutes but if you don't have one, assuming you and the DC are eating together, you can heat the oven up for them and he can figure it out.
Fajitas - wraps just get nuked as needed and everything else reheated/kept cold.
Chicken kievs or fishcakes - but I concede this is helpful as we have the air fryer so it's quick.
"no cook" pasta - cook penne and at the very end add a bag of spinach to wilt. Reserve a cup of the cooking liquid. In a bowl mix tub of ricotta, lemon zest, olive oil, chopped garlic, salt and pepper and parmesan cheese. Add this to the cooked pasta and spinach with some of the cooking water and it's done. DH can nuke his when he gets home.
Chicken tray bakes - served with mashed potato and veg. Easily microwaved as needed but do take a bit of time to cook so depends on if you have that time.
Any other pasta dish as really, all can be reheated notwithstanding what Italian chefs will have you believe.