Actually, no. No such claim has ever been made in an official capacity. There is an email reply supposedly floating around where Gabe hypothosizes that they MAY deactivate the authentication servers, but there is no proof whatsoever to back up the validity of that email reply. For all we know, it was created by someone else and never originated from Valve.
The response I was thinking of was part of an interview actually - I read that interview several years ago and it also defended other aspects of Steam. God knows which interview though - I think it was on Gamespy or IGN or something like that but Googling turned up nothing (Valve have gotten way too much press to find that exact article). I also read a forum post from a Valve employee (one of the big guys over there) stating a similar thing so it's not some vague email. I read both with my own eyes. A forum post and an interview may not be the best sources to quote but still ... .
As for 3rd party DRM activation, none of that is done by Steam's authentication servers, but by the client itself. The systems are completely separate and not even dependent on the content servers. So again, IF anything happened which resulted in Steam vanishing and IF the requirements for online activation via Steam were removed, the activation systems for 3rd party DRM such as SecuROM would remain as is. Either being done automatically on first run or via the activation request pop-ups -- none of which are controlled by the online components of the Steam client or infrastructure.
You seem to forget that Steam skips a vital bit which makes the above untrue: Steam does the installation and authentification for you at the moment - it auto inserts the cd key for activation after downloading the game. Remove Steam and tell me what you'll have? You'll have an installed but unactivated game with no way to activate it. And guess when SecuROM games are activated? During installation. And guess what you wouldn't be able to do? Install the game since you have no installation files - you got a pre-installed folder minus registry settings or anything else that gets installed during installation. All that is handled by Steam prior to you first playing a game.
Do you know what will happen when you try to run these games? You'll get an error that the game has not been activated and that's it. You won't even have the cd key even IF it lets you activate because Steam contained that cd key. But you won't be able to activate the game without Steam simply because you don't have the option of doing so unless you were to reinstall it which, without Steam, is not possible. I hope that makes it clear. Unless they release software that lets you manually activate a game AFTER installation, the current DRM will not do as you claim.
