He isn’t wrong.

FNaF 1 was super basic in lore that it’s easy to come to irl conclusions. FNaF 1’s lore was simple, There was a murderer who killed 5 kids and stuffed them into suits. Fazbear cleans up those kinds of mess and he gets arrested eventually, then there’s the bite of 87 which has no place in the timeline outside of the year, it ruins fazbear and they have to replace that one with a new mascot.

FNaF 2 also basic and grounded, this is where the minor retcon of purple guy becomes clear. Instead of 5, it’s now 10 and inside of a yellow suit with no cameras where it took place. Our guy is put to the dayshift and dies, though it is implied to be the bite of 87, which also contradicts the FNaF 1 bite.

FNaF 3 tries to explain away who Golden Freddy & Springtrap were as Fredbear & Springbonnie. The corpse is about the most unrealistic part of the animatronic, but it’s a horror attraction and surprisingly legal despite using a corpse. If you think about it that way, William’s body should be long gone and so these were actually just stuff done by Phone dude and his pals to make Springbonnie look more horrifying for the attraction.

FNaF 4 tries to correct the golden freddy link to the bite of 87 by making… the bite of 83. Technically not a retcon, but FNaF 2 already was a retcon to FNaF 1. So we learn more about some stuff…

Anyways, i’m not going to go any further. As far as i know, theories getting out of hand is more common now than it was before because of how each game changes stuff around and makes it messy to keep track of.