I'm quite surprised to hear that. We've had such restrictions on a number of occasions. I think I was wrong earlier when I suggested they were introduced after the Leeds FA Cup game. I seem to recall that Stoke away was a coach-only voucher affair a few weeks beforehand.
The only games these restrictions have applied to so far have been trips to Stoke, Millwall, Bristol City, West Ham and possibly Sheffield United (not 100% sure - I didn't go to that one). But Leeds will certainly be a coach-only trip, no doubt about that.
They are a pain in the arse, but that said it was actually reassuring to arrival at Millwall this season as a part of a large well-policed convoy of coaches (even if we were late for kick off). In 1999 I was one of 950 City fans who travelled to the New Den for a league game. 900 went on the train under heavy police escort, while 50 of us made our own way there on a big red bus with 'Pontypridd' written all over it. I have never been so frightened in my life at the end of the game. We were very lucky to get away from the area unscathed, although our bus took a bit of a battering in the process.