Seth Rogen has publicly discussed gaming in interviews (e.g., Hot Ones, Conan)—he's mentioned playing Call of Duty, Halo, and Mario Kart with friends.
However, he has never shared his gamertag. Celebrities guard handles to avoid swatting, harassment, and impersonation. Any "SethRogen" tag you see is a fan or troll.
If you want to game with creators, check out OfflineTV, 100 Thieves, or Game Grumps—they stream multiplayer lobbies regularly.