The thing that is actually a concern is whether third party series with more than one character will eventually get more uniques, and not just echoes. Otherwise, it might pose a problem for fans who want favorites from those series.
Gotcha, I do think their claim of Minecraft being leakbait being a little too convenient for their own good, but while the TGA claim was a mistake, they where hellbent on Erdrick/Luminary being part of the DLC for a while, and while Hero ended up being a little more than that, I do think they've at least proven to have some degree of reliable info on the matter. I won't count Banjo or Terry to their favour, but he did technically jump on those before their announcement, for whatever that's worth. I don't think at the very least considering their claims likely is wrong, at least I'd take their word more seriously than the countless other leaks that've come and gone throughout this entire period since Ultimates announcement.
Tansut was the only leaker who was on nearly 100% on the mark in regards to Hero, given how he leaked Cloud last time as his only other previous action. The only thing he got wrong was never getting a reply from his contact in regards to asking if Erdrick was in, because Erdrick wasn't actually the base character, Luminary was. Everyone else was pretty much either sourcing him or doing an educated guess (or, more absurdly, taking Shinya Kumazaki's DQ collection on Instagram as a hint that Hero was confirmed).
At any rate, Verge's track record is 50/50 at best. Sometimes their sources are good, other times their sources miss crucial details (like Isabelle not really being an echo), and yet other times the sources are flat-out wrong (DBFZ in general, K. Rool, Cubivore pig being confused for Minecraft content).
Verge really did mess up in regards to assuming the Ender Dragon would be a DLC boss on day one though, that one's entirely on them.