Currently, public sub counts are abbreviated in most but not all places across YouTube. In August, we’ll make this more consistent by always showing abbreviated sub counts publicly. Creators: You’ll still see your full sub count in Studio! Learn more → http://yt.be/help/abbrev-count …pic.twitter.com/pmaKk4EU4k
I think that on the subscriber count should not be abbreviated on channel pages. Only abbreviate the subscriber count on places that are supposed to be simpler, such as the subscribe button.