With Disney releases you have to assume they're scrubbed of grain, have frozen backgrounds and more tampering in an attempt to make old films look like digital ones.
That said, I doubt they'll ever fuck up on that level again. Apparently the 4K releases of SitS and The Black Cauldron on Disney+ look pretty accurate, but don't take my word for it.
Personally it's really fucking hard to watch the remasters of these after seeing how non-revisionist labels release their old animation. SitS gets brought up a lot but it's far from the only victim.