It's still a relatively niche device. Antutu popularity on its site is targeted at a niche segment of enthusiasts. Popularity on an enthusiast niche benchmarking website doesn't equate to popularity at retail sales wise. Do you honestly think LeEco 15 was the 9th most popular handset in reality ?
All that chart proves is that more Note 5 users ran Antutu benchmark, and given the correlation between niche powerhouse devices and a niche benchmarking enthusiast website it stands to reason, but in real world if popularity = sales, that chart means very little.
Especially given the Note 5 didn't even launch in a huge segment of the world market.
Whilst undoubtably the Note and the rise of the phablet in general has been massive, the Note is by comparison still aimed at niche demographic audience.
That general audience for larger devices has grown, but since regular phones and those even budget devices like the Moto G have all grown in size over the years, they have filled much of the gap for demand for just bigger devices.
Samsung seems like it's trying to bridge the gap between its more popular commercially S7 and specifically the Edge variant and the Note. Last year Edge + replaced Note 5 in Europe and globally sales were greater for Edge + variant overall than the Note 5, this year they are clearly making a hybrid and giving us a Note 7 with the edges (and no separate edge +).
The danger is potentially will that take away too much from the Note, will it be more edge than note and if internals are same as the S7 Edge other than modest increase in screen size and s-pen what else can it differentiate itself with ? If anything Samsung could potentially be alienating many existing Note users, and those wanting a large Edge device may simply opt for the S7 Edge which is now readily available much cheaper at retail than it initially landed at and readily available second hand and on classifieds.