No, the superposition is a real physical thing and not just a probability distribution, the particle is in all parts of the superposition and not just randomly at one of the spots, we can see in experiments that it is in every spot. If you measure it then the superposition squared is the probability distribution of where you will find something, but it isn't just a probability.
This is what makes quantum mechanics hard, if it was just a probability distribution nobody would find that vexing its just a normal probability.
To me 'probability distribution' could be interpreted as a bunch of classical particles whose emergent behaviour resembles a wave in some way. Or a series of observations of a classical system whose errors add up to some wave-like phenomenon.
But others in this thread have mentioned that you can interfere a single electron with itself (which to my mind rules out classical-phenonema-which-appear-quantum.). And 'superposition' seems like a better word for that.
