I don't think anyone claimed people were coming back in droves. All you have to do is look at recruitment for some of the more active guilds. They recruit for the same position for week.
"Looking for top notch rdps!"
Will you settle for mediocre... cuz I'm your guy!
The community feels about the size that it was during the release of Tanaan.
Honestly, I don't understand why people continue to try and revert measuring success into sub numbers. Except that it allows you to continue the narrative that WoW is dying and the developers don't know what they are doing.
However, assuming Legion is doing "slightly" better and the last known number was 5.5 million, so that new number is greater than 5.5 million, means that Blizzard has stopped the bleed, and that they are now sustaining a player base that is still double WoW's greatest competitors.
What is the point of this dialogue beyond the usual doom and gloom that comes with a quarter report. As soon as you see a year with a loss on the financial statements... then you can head for the lifeboats. But even that doesn't signify the end of a dynasty.