I wonder if this is now becoming more common elsewhere, or not ?
The "one year" thing is based on a typical WT/JW mis-reading of Corinthians, not understanding that the guy spoken of in 1 Cor is not the same guy Paul is talking about in 2 Cor. Anyway, why should this case, if it were the same guy, dictate how cases are handled inthe 21st Century, each case should surely be treated individually. (Not that I agree with the DFing thing hardly at all).
I think they do not want people out on a limb for too long, they have probably learned that being out for awhile many never return, and it's real hard to make a convert to replace the lost contributions, far easier to pick the low hanging fruit and get 'em back in quick.
If they want to use Corinthians as a basis for doing this, then six months or so could be argued for, many leading scholars think that 1 Cor. was written in the Spring of 55 CE and 2Cor. in the Fall of 55 CE.