It is fair to expect that at least some of these and more other fruit varieties will eventually disappear from human consumption replaced by others evolved and developed superiors that constantly compete for human preference for evolutionary reasons. Ok, a lot is packed in that sentence but please do not argue, it is just an opinion.
The question is: what fruits were very wide spread in the past but all but disappeared from human consumption by now and why ? I bet there are plenty of examples. They are also likely candidates for worst. Anybody can give a brief history ? Any lessons learned ?
There is no evidence to suggest that either noni or cannonball fruit were ever widely eaten by humans, if that is what you are suggesting? Noni was only eaten by Hawaiians as a survival food in case of dire food shortages. The Hawaiians brought noni to Hawaii in original canoe introductions not because of the fruit but due to the other parts of the plants which were used medicinally and as a dye.
Cannonball fruit is found here at practically every large botanical garden, and nobody ever eats them. In Rio de Janeiro, oddly enough, the cannoball fruit was used as a landscaping tree in some parks. Again they are not eaten there.
As to fruits dropped from cultivation, i think what rather happens is that inferior fruits were bred and improved, as in case of wild apples, crab apples. Maybe medlar is an example of a fruit that is almost lost to cultivation?