I'd urge him to do so if asked.
Why weren't you concerned about it before I asked you? Why no thread about old Fred and Mary Ann? Why don't you ask him, instead of saying that he should do it only if he's asked? Why didn't the concerned Trump volunteer to do it on his own?
1. Because most people understand NBC to mean “born on U.S. soil as a U.S citizen” (putting aside anchor babies for the moment), so it wouldn’t matter if his parents were citizens at the time of his birth;
2. Because there’s no reason to think that his parents ever lived outside of the U.S., much less gave up their citizenship in the process of doing so, unlike Cruz, whose parents we know for a fact were living outside of the U.S. for years before and after the time of his birth;