I don't know if it's me but I find this sentence quite confusing in its current wording: All slots on the old cluster must be usable, i.e., there are no slots whose pg_replication_slots.conflicting is not true.
The prerequisite is that no replication slot has conflicting=true right? So this sentence (the i.e. part) suggests the opposite, as per my understanding.
I've copied the committer for this. Removing the "not" is simple enough; though writing in the negative sense, while good for an SQL where clause, does make reading in English more difficult. Would rather say "all slots must be false" rather than "no slots can be true". The next item regarding no persistent slots has the same complaint though it is factually correct as written. Though NULL is a valid value here so maybe the negative phrasing is indeed necessary...
