Lol. A theory without any evidence is just bullshit.
Tony doesn't want to believe that Challenger is worth a million bucks and his cobbled together rusty garbage isn't. So, he has to make up stories to discredit that car to make himself feel important. And because it will probably get him more views. But it's all just BS so Tony can make a buck on his channel. Bottom line is he's just jealous of that really nice hemi Challenger.
Are the stories about the "Black Ghost" probably embellished? Of course they are! Just like any old days racing story is, the story that "the older I get the better I was" is absolutely true. Does the Black Ghost have to be faster than all the cars it raced to have racked up a bunch of wins? It doesn't actually. Street races against amateur driver's depend a lot on the skill of the driver, the fastest car definitely doesn't always win.
Bottom line is it's a really nice, single family owned hemi Challenger with some cool nostalgia behind it, and people will pay what they want to pay for that. And Tony will try to inject himself into that story, because he's trying to graft a few bucks out of it.