The first Telegraph Road was a Shiraz 2009 and I bet it still drinks well though it will not improve. The sign of a good cellar is when budget wines improve to a point and then hold that point for a long time. I recall great success with keeping Jacobs Creek and Penfolds Koonunga Hill for a few years to mature.
Then along came micro oxidation a process to speed up the impression of cellaring so these days do not keep budget wines. Glug of course does not use micro oxidation so this Cabernet will improve. A driving force of Glug is to make the best budget wines possible and this Telegraph continues in this fine tradition.