FLCH is a special situation. When the throttles are manually overridden in FLCH, or they automatically reach the idle stop on their own (for an idle descent), the FMA will indicate HOLD and the throttles will not re-activate if the speed gets slow (unless or until you reach the MCP altitude you are heading for -- then they will go to SPD||ALT).
[This is assuming the A/P is disengaged].
Last edited by cf6-80c2b5f; 5th April 2016 at 01:26.