Everything can and will be justified Prisoner style as a Mind Screw to get Thomas to accept the conspiracy's logic as they're trying to master the art of Brainwashed and Crazy.
A lot of the Mind Screw makes sense if the Conspiracy is just screwing with their already fake personality of Thomas Veil. A real person is a lot harder to make disappear.
If Thomas Veil never existed in the first place and, his identity was created by the Conspiracy out of whole cloth, what does that say about the other erased people Tom met? At one point Tom met a town full of erased people and a man who was erased by the Conspiracy over twenty years ago. Are we to infer that these people were also brainwashed to believe they were someone they weren't? There is also the episode "Father" where Tom meets his estranged father (whom he hadn't seen in twenty years). The episode strongly implies that the man really is his father and not just another Conspiracy plot. Was this just more mind games by the Conspiracy?
They could also be agents of the Conspiracy lying to him.
It's possible that the Conspiracy had erased people in the past, just not John Veil.
Thom's dad (and thoms name) was likely real though. everything else wasn't...maybe
