Your plan
What your plan changes on its own
Two things change on their own. Your training paces follow your race fitness, a small step at a time: at most two points of race fitness in any seven days, and Home says so once when they ease. And when the organisers of a race you picked move its date, your plan moves to match and Home tells you once.
Everything else changes only when you choose: your goal time, your race and race day, your run days, long run day and weekly miles, your plan length, a pause, a new plan, a workout you move, add or delete, and the coach's suggestions, which wait until you tap Update my plan.
A missed run moves nothing. A run later the same week on a day with no planned run makes it up.