Just got a 2012 A4 (pre facelift) with a 2.0t CAEB motor. Ive been reading alot about the timing chain problems with these motors. I haven't seen anything about the 2012 model failing. Should i change out the chain / parts anyway? when did Audi update the tensioner design?

 

It's the chain, itself, which has been 'upgraded'...not the tensioner. Although, the tensioner and guides do get replaced when they install the new chain. Apparently, the new chain is supposed to resist stretching better than the old one. If you keep up with your maintenance, I wouldn't be too concerned about it unless it triggers a CEL.