They cannot sell the engine - even if they have changed it so much. BUT: They could sell the tools they created. Basically it would work like this:
- engine is free (kind of open source)
- you will be using AWS
- you get all the stuff like meshing et al for free (tied to AWS)
- the tools that generate stuff or manage stuff will be sold by CIG
So you could use the engine and create game without paying CIG a dime but you do this at a high price (doing everything manually) which limits the size of the game you can create with all manual labour. If you want to construct something like the size of Starfield you either license the CIG tools or you fail.
You also could design the stuff you need for MMO being not part of the engine (would makes the task more complicated as you cannot fit the engine into what you need). Maybe possible but greately increases the complexity (but also will increase the money you could draw off these features).
DONT FORGET: To sell something, it must work. The current bug shit is very difficult to sell. Its not obvisious if the engine works and the devs at CIG are total idiots that create all the bugs on top of the working engine OR if the engine itself is bugged.
Games are a software project, nothing more, nothing less.
Idiots like jared try to deny this and come up with tactics trial and error as normal part of the development process.
If you develop software with trial and error, you are already on a wood way (germans used to say). If you need to summon the “games are special” vibe you dont care about software engineering the slightest and your output will be pure shit on many occasions.