When you update the change monitor report metadata filters and include new metadata types, the next monitor report shows all the newly added metadata as "New Items" on the report. Although not a big deal it did cause an alarm for us not realizing it was due to the change we made prior. It would be a "nice to have" feature if either you don't include the newly added metadata types as "New Items" on the initial report or flag them and have a visible cue to indicate the items were a result of newly added metadata items on the report filter.