Big ups to skywatcher for putting out an article so quickly, hopefully when this plane finally catches the attention of other outlets they will source back to your blog!
Although it's probably worth rephrasing the title as "watch this space" or something similar, because we don't actually have photos of the thing yet, nor confirmation that it flew, only that it's probably under advanced development.
Good job estimating the size of the aircraft too, using the SATCOM dome. A 1 meter diameter for the dome is a reasonable, or even conservative guess -- it's similar in size to that of most MALE and HALE UAVs like Predator, Reaper, Global Hawk, and I think the gleaned length and wingspan is quite reasonable based on that premise.
But god, a 25m long, 50m wingspan UAV would be massive. That wingspan puts it bigger than 737, Global hawk, and up there in the class of B-2...