For what its worth...
The reason they won't run Altrincham services through Piccadilly is that the Bury-Piccadilly ones cant go down Market Street. So they have to go somewhere else and Metrolink decided that they should all run to Altrincham instead, like they did last month. Therefore there's already a 6 min service from Altrincham and no spare trams to run Piccadilly as well. Maybe the right decision, maybe not. I get it's not intuitive given the actual track/roads are open....
What's not right is the fact that they didn't personally contact two of the posters on here to ask their permission up front, and perhaps guide them all the way to and from the stadium. Imagine relying on all the posters, signs, tram-front destinations, websites etc that a couple of people didn't look at....