You're missing one CRITICAL point in your "theory": Harry Potter IS the CHOSEN ONE. In the prophecy, it is stated that "the Dark Lord will mark him as his equal". This is not only speaking literally about the scar, but moreover and specifically speaking as to the CHOICE that Voldemort makes in selecting HARRY to be his equal.
Had Voldemort gone after Neville instead, then the same fate would have befallen him. However, seeing that Voldemort CHOSE Harry, that remains that thereby changed Neville's fate.
Yes, in a parallel world Neville could have been chosen, He was however NOT chosen. Leaving your theory completely moot.
And as was previously mentioned by several ppl in this comment thread, had you actually read the books thoroughly, you would have seen that Harry had been made aware of this fact well before the final Hogwarts battle. (A fact that was spliced into the final few minutes of the final film).
The fact that Harry knew that he was chosen by Voldemort is something that he struggles with. He also looks upon Neville with newfound sight after this. He has a new respect for him, and also envies Neville that he was allowed to have a chance to know his family before they were hospitalized. (Remember, Neville's parents are still living in St Mungo's Hospital).
So why you felt the necessity to film this trivial video and post it as though you are some brilliant sleuth who stumbled onto some facts that the rest of the planet missed is simply silly.