They almost never use a laserdisc for a DVD or Blu-Ray except in rare cases. They are usually component or composite masters. Star Wars was D1 component for Gout. I have no idea if Fantasia is D2 composite or the former.
Correct the theatrical OT Star Wars dvds used the same masters as the 1993 laserdisc boxset and the 1995 faces laserdiscs.
Whatever the case with Fantasia, the pal dvd is obviously superior to the LD, as seen in the comparison shots.
My guess is it’s similar to Star Wars.