OK, sorry for the rude comment. It was over the top, I admit.
As to your question, here are better examples than what I gave before. I think that the week before a trials meet would be (slightly) different for a Robby Andrews with vs. without Matthew Centrowitz entered, or for a Boris Berian with vs. without Clayton Murphy entered, for Ben True with vs. without Paul Chelimo entered, or for Meb Keflezghi with vs. without Galen Rupp entered.
I am not saying that they should implode upon seeing the superlative national champ on the starting line, or overhaul their final week of prep. But strategy and final preparations for a runner who may be on the bubble will not be indifferent to the champ's presence in a top-three-qualify format!