I would've put it in Animation Courtyard. Have the queue consist of walking guests through the former animation workshop and the pre-show is changed to being a newly finished Mickey cartoon.
Can't say I blame them. Runaway Railway has a lot of elements I like but it's ultimately a subpar ride in a spot it doesn't belong in (at least at WDW).
This conversation makes me wonder if they'll consider adding MMRR to the parks or not. I don't think they will, if only because there's no space left in Mickey's Toontown.
There's a rumor that Tokyo's Splash is getting rethemed to Duffy. Again, it's just a rumor but considering the lack of advertising Tokyo's version has been getting it may as well hold some truth.
Hopefully it does. Because unlike Song of the South's cartoon characters, there is little to enjoy in Pocahontas that can be divorced from the original source material. Maybe a song or two but that's it.