That’s pretty much how I expect things to go as well. Russians have a long history of imprisoning and outright murdering any POWs returning to Russia – they know the stories the POWs have would run counter to the bullshit they’re fed, so it’s easier to just get rid of the POWs if they don’t toe the line.
And it’s not like this is the first prisoner exchange that’s happened during this war. If released POWs were actually capable of changing the narrative, they’d probably already have done so.