First Cymru have recently announced some service alterations on their website
These are due to start on January 6th.
Stagecoach, as previously announced, are altering a few of their services to take place from December 1st. This is their service update page:
Note the amendment to service 120/130 is an old update, not the one to be implemented next month. So far, there's nothing to tell the public that a few services are due to change. Recently they added a 1600 service 172 from Aberdare but didn't mention a thing on their website. The current 244 timetable is showing as the one that will commence from Dec yet nothing alerting any users of the route to the fact that it is due to change. One beauty on that screenshot above is the introduction of the rail road ticket from Maerdy to Cardiff, which was added to their website the day after they introduced the ticket!
Credit to First Cymru, Cardiff Bus and Newport Bus for always being on the ball with letting passengers know about updates to their services through their website. I can't say the same with regard Stagecoach, unfortunately.