I used the word "perhaps" as I have seen in years gone past CFM powered 737 classic taxi in with one engine shut down when reverser stuck deployed.
(I didnt ask which hyd sys powered the T/R)
I assumed as I am not licenced on type that with the T/R deployed engine idle would increase to flight idle making it a difficult taxi or it was to reduce FOD and jet blast for those arriving the aircraft on bay.
....Perhaps
Just thinking outside the box (cockpit)