A liner hanger is locked for run in to prevent accidental setting using a trapped collet assembly. The liner is internally pressurized to push a ring from which the collet extends. The collet heads leave a mandrel groove and compress a return spring while at the same time shouldering against an outer assembly that ramps the slips out on cones for a grip of the surrounding casing. Weight is released and the slips prevent the assembly attached to them from moving to hold the return spring compressed. Picking up weight releases the load on the slips of the hanger and allows the spring to retract the slips and return the collet assembly to the run in position in an exterior mandrel groove. This can be used with a relative rotation feature incorporated into the liner hanger to allow liner rotation during cementing, if desired.