I would argue that because MMT and YS have been remixed well and remastered for Blu-ray releases that it makes MORE sense that they would come out on CD/vinyl with some bonus tracks in the near future.
Half the work is already done! And yet Apple hasn't seen a return on that investment on the music specifically. Those were visual releases in the main.
Also, one would think with the film itself not aging very well, that Apple would be very happy for MMT to be thought of as an album first rather than a soundtrack to a subpar movie. Making a deluxe set focusing on the music helps to accomplish that.
Now, plenty of albums get re-released based on only on a remaster/remix and a handful of bonus tracks. We are spoiled to think everything Apple releases now needs to be like the huge White Album box.
A 2-Disc YS deluxe set (with a nice book) could include the following, and be a very worthy release, IMHO:
CD1
Original soundtrack album remixed
CD2
1. Yellow Submarine (with spoken word intro ~ Real Love single b-side)
2. Only a Northern Song (outtake ~ Pepper sessions)
3. Only a Northern Song (horn overdubs/studio chatter track ~ Pepper sessions)
4. All Together Now (outtake)
5. Hey Bulldog (outtake)
6. It's All Too Much (outtake)
7. It's All Too Much (original full-length version)
8. Only a Northern Song (mono unissued EP mix)
9. Hey Bulldog (mono unissued EP mix)
10. Across the Universe (mono unissued EP mix)
11. All Together Now (mono unissued EP mix)
12. It's All Too Much (mono unissued EP mix)
Blu-Ray
Hi-res and 5.1 of all of the above
For MMT, something along these lines:
CD1
Original US Capitol album remixed
CD2
1. Magical Mystery Tour (outtake)
2. The Fool on the Hill (outtake)
3. Flying (outtake)
4. Blue Jay Way (outtake)
5. Your Mother Should Know (outtake)
6. I Am the Walrus (outtake)
7. Hello Goodbye (outtake)
8. Strawberry Fields Forever (Take 7 + Edit Piece in Stereo)
9. Penny Lane (instrumental backing track)
10. Baby You're a Rich Man (outtake)
11. All You Need is Love (instrumental backing track)
12. Magical Mystery Tour (film mix with spoken word)
13. Shirley's Wild Accordion
14. Jessie's Dream
15. Aerial Tour Instrumental/Flying (9-minute version)
+possibly add some of the unbooted summer jams or even Carnival of Light, since side 2 of MMT was sort of a catch all for non-Pepper recordings from 1967 anyway....
Blu-ray
Hi-res and 5.1 of all of the above