Elementary, Mr. Watson. Deduction. Absence of barking.
You have no evidence. Just supposition. In fact, we have two pretenders who came later, one who may have been Richard of York but I don’t tend to believe in pretenders although one very good historian (Ann Wroe) does. I believe they escaped to Gipping Hall (where they were seen with their mother after Richard ascended the throne) and then to Scarborough and then onto the continent. Not unusual for royal children to be shipped to the continent during upheavals. His brother, George’s kids, also made that journey in earlier times. But this is supposition as well.
No one wanted a child king after the disaster of Henry 6.