There is evidence (or inference) that with the fuel metering valve open there was insufficient fuel flow to accelerate the engines
The reports seem to indicate that this was the case.
...thus whatever is in between, could be mismanaged either manually, automatically, by design, or unintentionally.
I've had a ponder about how you could
deliberately restrict (not shut off) the fuel flow to the engines and I can't really think of a reliable way of accomplishing this without some rather noticeable secondary effects (!). The main tank pumps can be turned off without affecting the fuel flow (at sea level, that is) so you'd have to put both fuel control switches to cutoff or pull the fire handles, then pull the CBs for the spar valves to try and freeze them in a slightly open position, then quickly re-instate the FC/FH... I don't know what the transit times are, so it might not even be possible. At that point the FBW, autopilot, electrics, etc. would have all gone for a ball of chalk, not to mention the RAT deploying. I think we can put this scenario down as "unlikely", at the very least!