These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Replacement Scrappy: Everyone in the weekend edition. Also, when Deborah Norville signed on in the late 80's and early 90's, the show went through some very rough times. Inverted with HER replacement, Katie Couric. Katie originally came on while Deborah took maternity leave, but since the ratings increased dramatically in her presence, NBC made Katie a permanent anchor.
The Scrappy: Since the firing of Ann Curry in 2012, Matt Lauer has become this.