That's what it sounds like, I know that Universal released a combined set of the Legacy Collection DVDs (in 2014). If Universal just recreates the DVD box set it looks the blu-ray collection will be the individual Legacy Collection releases in a large slipcase; the DVD set includes a 48 page booklet, I don't if that will be in the blu-ray version or not.
If you want to take a look at the DVD set, here's a listing up on Amazon with a couple pictures: https://www.amazon.com/Classic-Monsters ... B00L8QP082
EDIT: Well, now I can't find the links in either the Creature or Invisible Man threads in Blu-Ray.com's forums to info on a blu-ray release of all the Legacy Collection sets. Maybe it was listed as coming in error and the poster has since edited their post? Right now the only store listings that turn up are for individual Legacy Collection sets. So maybe no big set on the way currently.