I’m not sure how they worked out the rights, but I can tell you two things.
One, I was in Barcelona a few months ago and took a side trip to the Teatro Dali, which was nothing short of amazing. One thing I found there was a small room showing a fantastic video on a loop - I watched it twice and then said to my partner “this is amazing, it’s like Dali meets Disney” My partner then pointed to the wall (that I’d ignored on entering) that said “Destino, a collaboration between Dali and Disney” Ok. teach me to read. I wanted badly to own this piece, but it wasn’t available for sale in the gift store, online, or anywhere else. Last month I had a friend over who had never seen Fantasia 2000, so we put it on. I noticed for the first time, in the part with Angela Landsbury, a reference to “Dali made a short, comparing life to baseball” that was rejected. “THAT IS DESTINO” I almost yelled.
Some more searching.
The new blu-ray release of Fantasia 2000 has it. It is on as a “bonus feature.”
We bought the disc, but have yet to buy a blu-ray player - that’s going to be once the tax returns are in. Yes, we are upgrading our entire home video system because of one film short.
It’s available. I don’t know how they worked it out from two massive estates, but they did. I highly recommend seeing it.