Different shows' fates affect each other all the time. After all, they're competing for shares of the network's finite supply of budget and time slots. Star Trek was bumped to a bad time slot in season 3 because the producer of Laugh-In refused to give up its slot. FOX cancelled Alien Nation because they wanted to expand their lineup to more nights and could produce four half-hour sitcoms for the same budget they spent on AN. And often, whether a show gets renewed or a pilot gets picked up depends on whether the network has anything else to replace it with. Increasingly these days, with so many different outlets for shows, the number of new shows available to a given outlet has diminished, which has made networks and other outlets slower to cancel the shows they have, since they have fewer options for replacing them.
So, yeah, I can see how the decision to end one Disney-made show on ABC could increase the survival odds of a different Disney-made show on ABC, because now both the studio and the network can redirect the resources from one into the other -- or may have more incentive to keep the other now that they've lost the one.