More or less. There's a bit more nuance to it, and I was thinking particularly of the case of entangled particles at a distance rather than a self-interfering particle through a slit - but it probably resolves down to much the same mathematics.

Bell's inequality proves the simple ('realist', above) option can't be true, but the Copenhagen Interpretation is the most accepted interpretation of the alternative. Wikipedia lists three such interpretations, and IIRC "many worlds" is a separate one to the Copenhagen Interpretation. Though again, it's a bit more nuanced. When I was studying, I think they basically assumed Copenhagen, though not treating that entirely as settled fact, and leaving other interpretations as niche.