So Jo served in the avengers Part two under Marvel. She had a lot of respect at that time for Owen, and I think she would've given that same respect to Marvel and been complacent in the impersonation of Owen because she would've viewed it as doing a solid for Owen more so than as a fault found in Marvel. She stepped down from the avengers after the backlash he suffered, which she thought was unnecessarily cruel and out of line, so she quit in protest for him.
Jo's pretty accepting of a lot of things, because she's an alien more or less. So she would've accepted him regardless, and she is definitely super happy to see him back. Unfortunately for the both of them lol I'm super looking forward to a gamewide plot.