It wasn't "implied", it was "the writer gave an interview where he said Flex was meant to be Logie's son, but someone within Marvel decided Wolverine wasn't going to have a son" (oh, how things have changed), and thus all we got in-story was "you'll never believe who my father is".

As for Unuscione, they've never clarified her connection to Unus in-story, but I think one of the handbooks may have confirmed him to be her father.