Tony Gilroy confirmed Andor will be 24 episodes in total, over 2 seasons:
‘is going to be a story that spans five years – the first year of which will be explored in the 12-episode first season, starting this August. The now-confirmed second season will also consist of 12 episodes, spanning the other four years and leaving off right where Rogue One begins.’
I had thought this may be like The Mandalorian with multiple seasons, but should be interesting to see how this series evolves and how it manages the leaps in time for the 2nd season.
And looking forward to seeing a full trailer for this.