And they recently did the same with the Diablo 2 """remaster""", preventing multiplayer-heavy mods running in the regular online mode from operating !! (They are not allowed on battle.net, partially for anti-cheating reasons of course.)
Meanwhile other games still allow normal connection through IP/server name, provide a matchmaking server for players to organize their games, including modded ones, and provide an *optional* ban list for server owners using the official matchmaker to enforce on the worst offenders that in no way affects the singleplayer or the direct connection multiplayer experience !