nooluv
Just to clarify: An approach speed of 137 kts is the correct one (using flaps 15 for landing and corrected for icing conditions) according information given in #508.
But what looks strange and puzzling is the information given in the NTSB briefing that the aircraft - apparently - flew 134 kts without any flaps selected - an unusually low speed.
In any case ATC has no way of knowing what the actual minimum speed for an aircraft is, as the actual flaps setting is not known to them.