I can't even guess where TCan is going with this. When R1 was put out, it was a force. BR being put out erases any forces, as stated above, but does not cause all previously completed forceouts to revert. That way lies anarchy!
The statement earlier that "the rule stating that putting out BR removes all forces can only refer to BR being put out prior to reaching 1B" is faulty. In fact, an extremely normal play can illustrate this. R1 on first, fly ball to shallow F9. R1 is a few steps off first, when BR passes R1. BR is out (and beyond 1B). F9 fails to catch the ball.
Is R1 still forced to 2nd? Of course not.