I felt the shared history between Maul and Obi-Wan was wrapped up when Maul killed Satine in front of Obi-Wan. For me there was no more to it. When introduced in Rebels, all Maul has left is his hatred for Darth Sidious. He says as much to Ezra.
I did consider that Maul’s revenge on Obi-wan was murdering Satine, but he always intended Obi-wan to eventually die in a prison cell, so him still being alive after order 66 was unfinished business as far as Maul was concerned.