For in-memory database, the rollback to stable removes all the updates in the update-list that are more than the stable timestamp and it doesn't touch the on-disk key/value because there is no history store exists for the in-memory scenario. There are chances that some updates are written to an in-memory page that also needs to be aborted, but we didn't remove them as they will be taken care of later during reconciliation. But with the change
WT-5778, a tombstone with (0,0) that is globally visible is not added.
During the search of an aborted key/value, there is no globally visible tombstone in the update list and it leads to the reading of an on-disk value that is already aborted and lead to the test failure.
we need to fix the rollback to stable add a globally visible tombstone when their on-disk pages have aborted updates according to the stable timestamp for an in-memory database also when there is no valid update is found in the update list.