For what It's worth.

I spoke with a onepass rep this afternoon, upgrading a flight. He gave me an explanation on the partner upgrade changes.

Keep in mind this is far from offical, just what this one Continental Onepass rep said he was told.

As for the America West changes, they came at the request of America West.
The Northwest changes(platinums will be able to upgrade 3 days in advance) were a hold over from gold elites being grandfathered last year. He said NW didn't want to give the 3 day upgrade to non-earned platinums, and now that all the platinums are "earned" NW dropped their objection.