No, this isn't a reference to ~ATH Portal 2 and other Source-based games use the same key as a shortcut to the console, so it's just another case of The Stanley Parable trying to disguise itself as a Source game. Once this is done, you'll be able to open up the console using the tilde ('~') key. In order to enable the console, you have to type '-console' or '-dev console' into the Properties > Launch Options of the game on Steam.
14A - VANILLA CHEATS AND THE SERIOUS ENDING
