I agree. I think owlman being a traitor is very unlikely.
As of Thomas knowing and/or being in the Court of Owls is unlikely, You must consider it this way our Dick Grayson was born into a secret society that not even Bruce had known to exist, had grayson's parents not been killed and Bruce taken him in, our Dick Grayson very well might have become a Talon and assassinated people as villain.
The reverse of that would be Grayson 3 was born into a secret society that Thomas didnt know about, grayson 3 parents were killed and he was adopted by Thomas to become a villain, hence if he had not been adopted he may have been a hero.
third about beliefs, Bruce clearly thought Jason was dead and never coming back but Jason did and Bruce did not know for a long time while his enemies did. so someone shockingly coming back to life isn't unheard of in a Batman comic.
finally, cold did not kill the talons it just stopped their movements and regeneration had they been warmed-up they would come back to life. Also on the same token we have also never seen a Talon killed.
this is the new fifty two so there is nothing that state the court of owls is exclusive to this universe, there are many things in worlds one, two, and three that mirror or are slightly altered from each other their is no absolute proof the Court is any different. adding further the Trinity War was set as the first Universe wide cross over before the court of owls. So why of all names would they choose to link and the Court, if they did not intend them to be associated together considering they already had plans for Trinity War.
We don't know exactly what the Jokester said, He could have revealed Grayson's true origins which caused him to defect.
it is fairly obvious that they are going somewhere with this whole Thomas connection to Dick Grayson thing. so we must consider the options
One: Thomas cant bare another Dick Grayson being killed, when Grayson obviously escapes (he is seen fighting owlman and Ultraman in Justice League 25 cover )and Owlman defects to help Dick Grayson
Two: Talon is alive, big shock to Thomas. Helps our grayson or helps the JL comeback from Earth 3.
Three: Dick Grayson turns evil and joins the crime syndicate for no real apparent reason.
Four: Dick Grayson is somehow the key to defeating crime syndicate
Five: IDK what other options do you guys see