Reminder: XOX Leaks and related accounts are Dataminers, not leakers
Too often people wonder "how can we trust these guys if they got the thing about Ultron wrong". Or that the latest bunch of character leaks are fake or they are clout chasers.
From what i gathered, all the leaked characters post Season 0 have been datamined. There's little data about them but their names are found in the hero ID section.
To give an example: Here's Colossus and Paste Pot Pete:
What im trying to say is that im 90% sure any character they mention have been found in the files one way or the other, and i trust these will be heroes in the future. What you should also consider is that these account cannot predict when the content will drop. Going back to the Ultron thing, marvel leaks was so sure because they were working with an old patch that had ultron enabled and he was basically finished but instead he got pushed back so both Invisible Woman and the Thing were available in Season 1.
In short, the stuff these account say is reliable but what's not reliable is when its coming out, as the devs can change their mind during development and dataminers can't accurately predict that, that's why they got the stuff with ultron in season 1 wrong