I have contacted MO to get more details on the A B thing. They are closed for the holiday, returning 1/4. I will report back when I hear from them. Ryan - don't have a cow, man!
I think they are going to have to clarify that. It may be that they are identifying A and B for traffic management during the I session and the ability to run Twilight.
^You could run 190's on your 675. I ran them on my 600RR. Slight difference in profile and height. Mostly personal preference, unless there is a clearance issue with the swingarm.