The DB website shows all the morning Munich-Leipzig-Berlin-Hamburg ICE trains on Sept. 7 affected by multiple construction projects and notes that the trains would leave 80 minutes earlier (implied is than the departure time advertised on the "Reiseauskunft", but that's only sort of clear). It also notes that intending passengers should check the real departure times shortly beforehand. So you can either arrive for departure at 7:30 and get on the early-departing train or - if construction has been completed or delayed - wait until 8:50 and get on the train as scheduled, all depending on what the latest departure information is. Or you could arrive at 8:50 and either ride the train as scheduled or ride on the next departure (your ticket will be valid) if the intended train has already left. As other posters have noted, the DB needs someone who can write clearer information on their website - in both German and English.