Am I correct in understanding that in the many-worlds interpretation the Universe is considered as a single quantum object?

Among the tags there is also a topic of interpretation, so I hope that the question will not be closed. In the many-worlds interpretation, the wave function acquires an onotological meaning, that is, it becomes physically real. And since the wave function of the Universe is also considered in the cosmological context, does this mean that in this interpretation the Universe is a single quantum object (the same as, for example, an electron)?

A related concept is called the church of the larger Hilbert space which is essentially the statement that all states are pure once you look at enough degrees of freedom. Mixed states with $$\rho \neq \left | \psi \right > \left < \psi \right |$$ are an effect of looking at only part of an entangled system. The simplest example of this is again a Bell state which acts as a purifier for a single photon which appears to be in a classical admixture of horizontal and vertical polarizations.