Well it’s not officially confirmed, but Jason Aaron isn’t known for taking back his retcons. There was a scene in a recent issue where the Phoenix in the past says that Odin may need another child to mellow him out which I think is meant to imply that she is already pregnant with Thor. If I had to put money on it, I definitely would say it’s meant to be legit, which I hate.
It’s really a dam shame how Aaron is allowed to wreck and ruin one of Marvel’s most prominent and renowned characters. His whole Thor run was a disaster and his current Avengers run is equally as bad imo. If you’re a fan of chaotic and childish writing, this book is for you. As for his Phoenix “revelation”.. all I can say is THIS
Not sure if there’s some big Phoenix event coming up in the MCU (Echo/Phoenix?) and this is the revelation they want to run with. If so, a much better candidate for a Phoenix offspring would be Adam Warlock imo.