Airline routes/RoutesOnline
For the record, Airlineroutes/RoutesOnline is not “a blogger with a website”. It’s part of a highly professional and reputable company which (among other things) has been organising global route development conferences for the past 25 years. It’s internationally respected and has carved out a leadership position in the business of connecting airports and airlines.
Its data sources include paid/privileged access to GDS systems, so it is normally the first to pick up on schedule changes. Often before an airline will communicate with individual customers (particularly BA, whose IT systems are especially ropey).
I have no axe to grind on this (I’m not connected with the company) but I have worked in the industry for 40 years and I can vouch for their professionalism.