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
That’s just a bad idea. If this isn’t optional then don’t implement it. There’s literally no benefit to this. It doesn’t provide a cleaner look since the full number of subscribers isn’t in the way to begin with.