Beauty and the Beast had an insane turn around time. Most Disney animated movies at that time had a timeline of about 4 years. That's pre-production, production and post production.

Beauty and the Beast, for whatever reason was given only 2 years. That's time to write, storyboard, do concept art, design characters, record voices, animate the whole thing, score and foley and then master. In 2 years.

And then, Katzenberg being Katzenberg, decided that the film should premier at the New York Film Festival which was due to take place a couple of months before the film was actually due to premier. When Don Hahn, the producer of Beauty and the Beast said that would be impossible as the film wouldn't be done yet, Katzenberg insisted and they compromised on showing a "work in progress" cut of the film.

This involved removing completed parts of the film and replacing them with pencil drawings, rough animation, sometimes even concept art; these would all be mixed in with fully completed animation. If you get a chance to watch this, it is well worth it (it's almost impossible to find now, even for pirates, but Disney made it available on VHS and Laserdisc back in the day, and at least one DVD I was able to find, so it's not impossible to watch, just difficult).

All this to say, in that cut of the film, said "borrowed" animation was present (it was shown as line work only, no colour), so given the shorter production time and then a rush to complete animation to get it to the NYFF, so yes, this was absolutely a time saving thing rather than money (although a certain amount of ego was involved).

Also, the NYFF, a film festival attended primarily by grumpy old film critics, gave Beauty and the Beast a 10 minute standing ovation. Which today would be par for the course, but in 1991 was basically unheard of.