My ex husband was a "jr." I still get credit card offers for my first name last name jr. I also once had a really nutty phone discussion with a marketer where I tried to flippantly make the point that I can't be a junior since I got married and thus no longer have the same last name as my mother. They didn't seem to get it.
I thought I would escape my name issues by marrying. No dice. I thought I would escape them by going by my more common middle name. It doesn't help as much as I hoped. It's like a curse.
Perhaps it is too soon after waking up to have a sense of humor, but the flaw with your plan is that I am divorced and would be highly unlikely to intentionally have a child out of wedlock. And if I remarried, I would be highly likely to take a new name. (Though, given my post divorce relationship track record, the new name would probably be foreign and something I couldn't spell or pronounce, much less other Americans.)
Glad you brought that up—my father is a third, and my mother didn’t change her name when they married, so they both have their share of name-handling issues. Makes me almost glad to be boring old Jon W. Purdy.