This is a good question and one I was going to pose myself, the email states the plugins are now available to use on other DAW’s, and all that was needed was to login in and visit the presonus shop and download for free if you was a presonus sphere or Studio One 5 Professional user.
After trying multiple times loving in and out I couldn’t find a free version of the plug-ins in the shop, going by the comments I see that others have found them already in Studio One, but still makes no sense to flash send a mail, but not follow through with it.