Earlier quoted context omitted.
Wikipedia sources the claim to an article by Jerry Pournelle in BYTE magazine, from 1985.
Here's the snippet in question from the magazine: https://imgur.com/a/8SVQGnj
"I'm told there is a relationship, but I can't prove it."
John knows who his uncles are. His father is Walter Charles Dvorak born in Minneapolis to John Steve Dvorak (also born in Minneapolis). August Dvorak and all of his siblings (none of them Walter) were all born in McLeod County to IMMIGRANT Joseph Dvorak. If there's a connection it goes back to Bohemia.