This seems like a good, if belated, move on HPs part. Ethernet switches have become trivial to build with off the shelf parts. If you open up the software then you can focus on things like build quality and reliability.
This hasn't been true for a couple years now, at least for top-of-rack and spine switches. White-box switches are now accessible to the general public, have low margins, and are not limited to huge purchasers like Facebook and Amazon.