The HL3 memes don't even seem fair to use anymore. I don't even want to un-seriously make joke fun of them at this point. They are just genuinely doing so much for the community.
(answer: probably, but I would like to believe that this is one of the greatest unintended marketing tactics of the 21st century).
it's like Nintendo having a Mario game for their new hardware, e.g. Mario 64, etc.
there weren't that many teases, nor is it great marketing; CS:GO competitive e-sports is better marketed and probably made Valve more money than any HL wink-wink-nudge-nudge ever would.