Well I am huge fan of Dune ccg and would not mind if there would be a 2nd edition lcg for it. Even if it would be somewhat incompatible with the original.
Dune ccg is old, is has less cards than GoT lcg has, and we still play it. So it is easy to see that older version still will be played a lot!
Rotation is must as it has been said above! Otherwice the card pool would be again a huge mess... So the 2nd edition has very good chance of being much better in the long run. But it will take years ntil the card pool is even near the fullness of 1st edition. So original will be the "better" game for a while. Sooner or later the streamlined new version will run past, but it will take a time. (a lot of it...)
The GoT is dead. Long live the GoT!