I haven't seen an iota of information that affirms that having parents separate or divorce and then reunite is preferable than parents just staying divorced.
Having, as I once posted waaaaayyyyy back on #1 or #2, read about 500+ social and clinical psych articles on divorce as part of my research assistant duties for a well-known conservative social scientist who wrote a couple books on the economics and politics of marriage and divorce, the reason you haven't seen "an iota of information that affirms that having parents...reunite is preferable" is because there isn't any.
No one's bothered to study it systematically because there are no good data on the number of reconciliations (second marriages between same partners are not enumerated separately in state records), let alone the number of reconciliations that wind up -- Liz Taylor and Richard Burton-style -- in second divorces from same spouse. Plus it would be hard to suss-out why good-second-marriage-to-former-spouse would necessarily -- and "necessarily" is necessary because in your original query you're looking for affirmation -- be better than good-second-marriage, full stop.
