While we already know McGregor’s character of Obi-Wan Kenobi is getting his own spinoff show on Disney+, this is the first time we’ve heard about his supposed involvement in Andor.
It’s important to take the announcement with a grain of salt, since there’s no firsthand quotes or sources to verify it.
Obi-Wan’s connection to Andor could be explained by Senator Bail Organa, with whom the character has a close relationship with.
The last we saw Cassian was in Rogue One: A Star Wars Story.