The Superstar releases are single disc.
There are eight of them.
Most have mostly new shorts. Some have one or two previously released titles.
The Tweety release is ALL previously released content
I own the six GCs, the three PCs, and seven of the eight Superstars discs ( the eighth 'Tweety/Sylvester' was a full duplication from the GCs).
What hasn't been released is one of my favorites- Hare Brush ("my name is Elmer J. Fudd, millionaire. I own a mansion and a yacht"). Still waiting on...
Ron,
I'm not seeing any answers to your question yet.
The simple answer is no, not all the shorts on the six Golden Collections are on the Platinum Collections.
And there are several shorts on the PCs that aren't on the GCs (primarily finishing off a character's set - Marvin, Witch Hazel...