I’m certain this has been covered in the discussion thus far, so I apologize for restating the obvious again.
I still think AD is working toward coming back, and the timing actually makes sense. Let the Rams get through camp, evaluate and trim this roster, deal with any injuries and potential FA needs, and then restructure AD's contract once they have a clearer picture of the final 53 and their cap needs.
AD essentially ran his own training camp during his 2017 and 2018 holdouts. He missed all of camp both years and still came back and dominated—especially 2018, when he put up 20.5 sacks and won DPOY.
I also don't see AD coming back for some load-managed farewell tour. He's an alpha. He left the game as one of the best players in football, and I think he's training now to determine whether he can come back as his AD, not just contribute. With Garrett there, I wouldn't be surprised if that feeds his competitive fire even more.
I believe he keeps training, let the Rams sort out the roster and preserve flexibility for camp injuries/FA moves, then get the contract done as close as practical to the opener, maybe a couple weeks out. The longer timeline doesn't discourage me at all. It actually fits how AD has prepared in the past. Just my two cents. GO RAMS!!