Yes, that's correct...
To my understanding, it's true. Both Airbus and Boeing do not recommend single-engine taxi. But, the airlines (a.k.a the customers) have demanded that Airbus and Boeing come up with 'approved' procedures to do this...with the high cost of fuel and all. The aircraft manufacturers have satisfied the airlines with approved procedures...adding the footnote that single-engine taxi is not recommended, but also stating that there is "NTO"....no technical objection. This way, FAA and JAA are happy.
We've beaten this topic to death in previous threads. Is single-engine taxi safe? Does it really save that much fuel (money)? ....the questions go on and on.
At my old carrier (before my retirement), we did single-engine taxi as a 'normal procedure'. That is, unless circumstances and conditions prohibited it (as per the discretion of the captain), single-engine taxi would be performed...both in taxiing out for takeoff and taxiing in after landing. Few problems resulted, as far as I know.
Anyway, that's my two cents worth to the discussion...
Fly safe,
PantLoad