HIGHLY unlikely. Every year they produce at PTF tape for W2, 1099, T4 updates (call and order what you need as soon as you see it on the KG) and I have never known them to be "minimum cume" specific. We are currently at cume 11 but were on 8 for quite some time. In all other previously releases (this goes back to 5.x) we were ALWAYS quite a few cume's behind and never had trouble with year end issues. It may be possible that you have to be above (I'm just guessing) cume 4 or something but I still doubt it.
World A7.3 11 (quite stable and usually happy)
Attempting CO with Xe, AS/400, SP14.2 V4R5 (not happy)