This is nothing new, both Microsoft and Sony and probably Nintendo have been able to block the online features of console users who break the ToS or in this case two guys who got a bit to excited about the remastered Gears of War game they were testing and broke the NDA. I am pretty sure Steam would also block you from their service if you broke their ToS and yes your games would still be playable offline as they are on the two consoles, MP has gone for you. Although Steam just needs a new account to get yourself back online, bans from Sony and Microsoft would require new consoles.
Preordering I can agree with, the temptation to get the game on launch day can be high, but wait a few days, let the now mandatory day 1 patch be issued and then updated and grab a copy a little cheaper in a few weeks.