The site that you have linked is not an official
DCL site, and the wording they have used is a little different than that on the DCL site. For many years there has been a "members only" check in line for CC. It's not always any shorter than the "normal" line. This is still in effect, and is that the link is sort of mis-implying.
This is the statement from the DCL site:
Exclusive Cruise Terminal Check-In
Sail through the boarding process in a separate, members-only line.
It does say "boarding" process, but it also says "check in."
What IS new as of October is that Platinum CC members are allowed to board with the concierge group (automatic boarding number 1). This applies only to those people sharing a cabin with a platinum member. If you have 2 cabins and a platinum booked in only one, the second cabin does not get the priority boarding. Again, from the DCL site with "platinum" checked:
Priority Check-In at Cruise Terminal
Enjoy concierge priority boarding check-in at the cruise terminal.
And, yes, I am totally insane.....5 weeks from now my leaves will all be cleaned up and I will be at my muster station on the "Beautiful Disney Magic." Do you think I've heard way too many Cruise Director speeches?