They have done the same with the Libra 2. There is also a "
basic Sleepcover" and an origami "
Sleepcover", which are basically the same, except for the folding mechanism.
Also keep in mind, the developers are usually reserving "new" features for their latest premium line-up. So whatever Kobo is working on right now, will be implemented with the next Elipsa (or the next Sage, should they drop the Elipsa.)
So if this does turn out to be a successor to the Clara HD, it will most likely be "just" an update with stuff we have seen on other Kobos recently. (USB-C, Bluetooth, Audiobooks, more storage, 4-core Processor, Carta HD 1200, etc.)