Caution, proceeding post contains 3am cynicism
There's no way they'd shut down the TDU servers permenantly without express warning.
Apart from anything, there's no diabolical switch with "on" and "off" written on it linked to the feeble whirring box from the 70s they laughingly call the Test Drive Server.
Its a major consideration on their part. They'd stand to lose an awfully large amount of money from people who are still buying the game, of which there are many.
I expect some dolt on a smoke break in the server room tripped on a cable and yanked the little bugger out, inadvertently causing the 20 odd people who still play this travesty of a game to be unable to connect. I doubt they've even noticed yet, given the state they leave it in when they consider it "working".
Don't get me wrong, I love Test Drive. But the sheer volume of problems I've had with it tempts me on regular occasion to tear out my monitor by the stand and mash it violently into the printer beside it.
Today's bug tempts me in just this way.