I can explain this as I have been writing up these past two articles on this site.
Let's recap:
- Discs 1-4 cover Neon Genesis Evangelion with the Netflix dub and Netflix translation. The on-disc bonus features in relation to the TV series are also here.
- Disc 5 covers Evangelion: Death(true)² and The End of Evangelion with the Netflix dub and Netflix translation. The on-disc bonus features in relation to End of Eva are also here.
- Disc 6 covers the video format version of The End of Evangelion in Japanese with English subtitles. This version is basically very much the same as the original with some tweaks as it's designed to be like watching 2 TV episodes. Evageeks has gone into better detail than I can on that.
- Discs 7-10 cover Neon Genesis Evangelion with the ADV Films dub and ADV translation from what I have read. The original version of Episodes 21-26 is not included.
- Disc 11 cover Evangelion: Death(true)² and The End of Evangelion with the Manga Ent. dub and translation.
The collector's edition has all 11 discs, while the standard edition only covers the first 5 discs. I know Dai asked about the Classic dub's master but it should be the same as the Japanese Blu-ray HD master as the dub can sync with them (if they were going to use an upscale or SD-BD then it would have used less discs I reckon).
The only thing that would be missing would be the original version of Episodes 21-26 for the ADV dub and the original version of Evangelion: Death & Rebirth and also Revival of Evangelion that Japan has on their set.