No what happened to Half-Life 3 is they heard that Duke nukem was going to be released and they realised that the gaming community needed another game to be endlessly waiting for and that it needed to be in constant development and they realised that with steam and their other franchises they could afford to develop Half-life 3 for 13 years making it the game with the longest development cycle add in inevitable delays and you have a expected release date of 2021...
@TheVoxelman on twitter