So, I was hoping for a "Train travel for dummies" thread for simple questions, but I didn't find one...

I used DB for the first time last trip and really liked the convenience, ease and cost. Was a simple ICE train from FRA to Cologne, but now I want to try some more.

All seems pretty intuitive, but when searching for a train from Munich to Leipzig, I came across caution messages, two of which I am struggling to understand.

What does the "Train is running 80 minutes early" remark actually mean?
"Substitute stop Wurzburg hbf" - What stop is substituted for Wurzburg?





Seems all the options that don't include these caution messages take about 6 hours, compared to the 3 hour options with the cautions.

Any insight into if these are concerning is appreciated, especially the odds of "changes to the journey prior to departure.