I have a couple thoughts, not that anyone cares:
Without knowing anything about salary stuff, is it possible the FO told Connor that the team was shifting gears and he could either retire or get released? MM may have convinced JS that these moves ain't working and it's time to give other guys their shot.
Is this a midseason overhaul of the OL? Lucas is playing this week, Connor is gone, if Haynes is stepping in I think this might be a concerted effort to just start all over.
Yes, this is bad for any continuity, but it can't really get any worse for the OL. I mean, Connor stunk, Bradford stinks, RT by committee has sucked, Tomlinson has been bad also, but there doesn't seem to be an heir to take his spot.
At this stage of the season, I say give the young guys a chance to see if they can magically form an average OL together. Stranger things have happened.