I looked over the OnePass rules and I could not find anywhere that there is any mention of a 30 day hold time. So I think this argument probably wins: this was never something that was guaranteed within the rules, and thus there is no way to apply the "60 day change notice" rule to the "30 day hold" policy by incorporation.

To me, the rule / policy distinction has to be made. There are posted rules which CO should follow to the letter. These comprise a contract between CO and its passengers, who behave in reliance on the printed words contained therein. On top of the formal, printed rules are various policies through which CO implements the rules. CO should be allowed some freedom to exercise business judgment to modify policies in the way they desire.

The best argument I can think of, contra, would be as follows. That you should not draw the rules / policies distinction at the printed / non-printed boundary. That even some non printed rules may be of such a character that Onepass users rely, materially, upon them. You might argue this boundary would be more properly set as to those rules, printed or non printed, which have a "material effect on one's ability to acquire reward seats." So, a 30 day hold might be material, whereas elimination of the 800 elite number might not be, just as an example.

I think the latter argument, while colorable, is probably not the sound one.