quantum mechanics - Do consciousnesses get "scattered" across the many worlds of the MWI?

According the many worlds-interpretation (MWI) of quantum mechanics, following a decision with possible outcomes $A$ and $B$, with respective probabilities $p_A=P(A)$ and $p_B=P(B)$, a proportion $p_A$ of the universes branching from the decision point have $A$ occurring, while $p_B$ have $B$ occurring. That is, following the decision's outcome there are two families of universes, $U_A$ and $U_B$, sharing the decision point in their past and occurring in proportions $p_A$ and $p_B$.

If I understand the arguments correctly, where a given person's pre-event conciseness, $c_i$, "ends up" — that is, the kind of universe they will perceive continuity with following the event — is random: for all consciousnesses $c_i$ present in the single universe before the event, the probability that $c_i$ ends up in a post-event kind of universe where a given event has occurred is

$$P(c_i \in U_A) = \sum\limits_{u_k \in U_A}{P(c_i \in u_k)} = P(A)$$ $$P(c_i \in U_B) = \sum\limits_{u_k \in U_B}{P(c_i \in u_k)} = P(B)$$

for all specific post-event universes $u_k \in U_A \cup U_B$, and all pre-event consciousnesses $c_i$.

But what is the relationship between the specific universes where two pre-event consciousness end up? Is it the case that all pre-event consciousnesses end up in the same post-event universe:

$$P(c_j \in u_k\mathbin{\vert} c_i \in u_k) = 1$$

Is it even the case that they end up in the same kind of universe, e.g. that

$$P(c_j \in U_A\mathbin{\vert} c_i \in U_A) = 1$$

Or is all that can be said that

$$P(c_j \in u_k\mathbin{\vert} c_i \in u_k) = P(c_j \in u_k) = P(c_i \in u_k)$$

which is some unknown (presumably vanishingly small) probability.

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If the latter — if where consciousnesses end up is uncorrelated — then isn't it the case that after any finite time following the any "decision", consciousnesses that experienced the same shared universe prior to the decision will perceive different ones. Won't consciousness that are together now end up scattered across multiverses after a short time?