There must be a reason this is coming out now.
It's the kind of thing Democrats would have done AFTER Jeb got through the primary, so this is most likely the opposition research of a fellow Republican, and probably an inexperienced one, since this is a pretty quiet time in the primary process.
Either that, or Jeb is trying to get this piece of info out of the way and into the "old news" file before the campaign starts to really heat up.