After over a week of trying to get a meeting with @TeamYouTube we finally have one scheduled for an hour from now. If you have any constructive feedback to share with them regarding the abbreviated subscriber numbers (via the api), reply to this tweet.
The full number gives the ability for full communities to monitor the full sub count, it's great to be able to do as viewers and long time fans are able to count down and watch as a YouTuber reaches a subscriber milestone, with the rounding it stops that.