So it depends on the user, what they would use it for. There is no inherently bad idea, it is what is not being done which stands out based on what is being done. The support for the 21700 over the 26650 allows for a density improvement. The use of GaNi allows for density improvement. The biggest weakness of the Fusion 5000 was its size and weight, both of which can be improved if Anker just wanted to. There are those for which this Fusion 10000 is a perfect answer and I am doing my bit to let them get that by not ordering it for myself at the current discounted price.
If Anker had not wrote "Limited quantity" I may have ordered it but letting others get their who have the greater need.
What I suggest to Anker is release a revised Fusion 5000, let's call it a Fusion 5000 Redux which takes the current best density readily available technology and merges into something which won't fall out of a worn socket. Currently I solve that via either Powerport 5 or one of those small 12W and a USB cable.
I remind everyone who owns the Fusion 5000 what is the relative size
If Anker is listening what I would suggest is they make a lipstick size form factor, with the pins folding out from the longest side and the USB-C port opposite, so then any weight is not pulling out of the wall. Non-polarized pins then I place pins to bottom or top to fit around whatever else around the socket.
If you also wanted to add a flashlight to it then it becomes the "one thing you need" product with a 4" USB-C cable to your phone you can then pretty much if you only have a phone then just have that with you to last a long day moving this imagined Fusion 5000 Redux between phone and the wall socket.