Bottle shock does not happen to every wine, as a matter of fact, I believe that I've had it happen once or twice, and I make a good deal of wine every year.
I typically let mine sit a few weeks when I rack from barrel to demijohn, then another few weeks after I bottle. I bulk aged for at least a year or more depending on the wine, I prefer to do the bulk of aging my reds in barrels, and whites in carboys or demijohns. I usually wait a few weeks before bottling and taste the wine several times before bottling, this gives me time to test the wine one last time to make sure the wine is ready to bottle and that it doesn't need any more adjusting.
One of the main reasons to age wines prior to bottling is to make sure all chemical reactions have completed. If wine is bottled while fermentation is still happening, this can be alcoholic or Malolactic - I've had more than one wine go through MLF without really seeing any indication of MLF underway and only by doing a chromatography test did I find the wine to still be going through MLF, for a new wine maker it is easy to miss any signs of MLF, or any other process that might be underway, you’ll end up with a sparkling wine at best, or a potentially nasty (and explosive) wine if the wild yeast or MLB is a bad strain. Carbon dioxide created during fermentation has to go somewhere, if you have the wine bulk aging with a stopper and airlock, the CO2 can escape through the air lock, if you have it bottled and corked, the CO2 has no where to go, creating a very unstable bottle - trust me when I tell you from experience, it is a dangerous spot to be in!
I hope that this helps
