I think it did. A huge portion of GW2 was based off WvWvW. There was a time when the WvWvW player base was massive. Since ESO, WvWvW is all but dead. Be honest, how many of you know people (many people) who left GW2 for ESO? Now, how many of you know people who left ESO for GW2, nobody I bet.
When it became obvious to people that ESO had a better 3 way, large scale war product, people left GW2 by the guild. I believe this is around the time ArenaNet and NCsoft changed direction and pulled support from WvWvW. They also knew they could not compete on that front. They moved resources to Spvp, Raids, and Grind. They attempted to go where ESO wasn't. All that did was alienate the rest of their player base and leave them with major articles being written like "GW2 Apathy sets in".
At this point I believe the ship has sailed on GW2 due to the mark being missed so badly with the expansion. I don't think there is any coming back.
What do you think?