In this test, we disable the timeseries checks on each node and then create a buckets collection without timeseries options. However, due to the changes to make w: majority not wait for oplog application but just durability, we aren't guaranteed that by the time we disable the failpoint all of the oplog entries have been applied. This can trigger the assertions when those oplog applications do happen, thus causing a crash since the assertion is during oplog application.
The solution for this should be twofold - on the one hand, oplog application should trust the primary and should only trigger this assertion if the node is acting as a primary. On the other hand, the test should wait for the oplog entries to be applied before disabling the failpoints.