At some point it seems that SpaceX plans to retire the Falcon series in favor of the BFR (series?). For a fully developed and productive launch system to be retired due to improvements within the company line there must be compelling reason. If it comes to pass of course.
The Falcons seem to have reached one of their goals with 16 successful landings in a row. So are the accumulating first stages of a reusable vehicle to be left to rot when the new kid takes over? Seems quite odd to me. If the BFR series ends up as cheap to operate as projected, it’s just possible that the Falcons cannot be profitably flown by SpaceX when development becomes operations.
What about other launch providers. By the time BFR is fully operational there could be dozens of flight proven Falcon cores available. How many providers would jump at the chance of buying a first stage that could be flown repeatedly after some modifications of their own upper stages. It still wouldn’t let them compete with BFR. It would however, allow them to operate a national or corporate proprietary launch system for substantial savings without having to buy launches externally.