No, the App will lag behind a bit, it's quite normal. It may change later, the boarding pass is what counts and that is accurate. If you upgrade - or get upgraded - the first sign is often the boarding pass on the App after a refresh, but the front display of the App will continue to show the previous seat allocation. It's to do with where the data is held, which is quite complex to explain, but to oversimplify, the information sits on Amadeus for a long time and then once under airport control the master is DCS/FLY. The boarding pass is always DCS/FLY, the App tends to Amadeus.