If these come then I'll skip the purchase for Oblivion and Morrowind.
Dude, you might as well buy them because there is no hard ETA on these.
This project is a community effort and everyone volunteers to work on this. Therefore, there is no deadlines or any tight schedules like in a proper game development studio.
Plus, porting this is a gigantic task. You cannot directly port every object and character model from Oblivion into the CreationKit. That means that they have to create most of the assets, locations, enemy AI and quests from scratch. And at the same time, maintain parity with the original Oblivion. This is a lot of work for a community driven project.
However, even if this comes out, it still won't be on par with the originals, therefore it makes sense to purchase them anyway.