The first comment says that the double slit experiment is feasible under both hypothesis, but the second adds on that it is just as likely with MWI as waveform collapse.
Analogy: There are two possible bags arrangements, one filled with 5 green balls and 5 red balls, and the other with 4 green balls and 6 red balls. It's true that drawing a green ball is consistent with both, but it's more likely in the with first bag than the second.
I see what you mean. But I thought "ripples of one wave affected the other wave" was the accepted interpretation of the double slit experiment. In other words, the double slit experiments prove the wave-particle duality. I wasn't aware that the wave-particle duality was considered evidence in favor of MWI.
From Costanza's original thread (entire text):
Meta: