If it is an AA booking "ticketed", as mentioned before, doesn't mean a thing.

Where did you get that idea? Is there a written rule now? Seems to me the length of time an airline will hold a reservation varies quite a bit, and I've certainly reserved and ticketed much later than 21 days on.

Quite. I have had OWE reservations made months before with a hold date right up to a few hours before departure. I didn't wait that long to actually ticket, but that was my choice. Once they gave me only a one month hold, but a call to a supervisor fixed that.

On my ONE5, I was given a 21-day hold deadline by the AA RTW desk, but when I called to have it extended, it was no problem at all (no questions asked whatsoever and didn't need to involve a supervisor, luckily). My original hold deadline was 27-Nov and my new "deadline" is 27-Dec, but I'm guessing I could get that extended again.

The only caveat is they said that my fare would have to be re-calculated after the original hold date (27-Nov). So, I guess the only risk is that the fare will go up the longer I keep holding it. Of course, I guess there is also the risk of rules changing (?).

How long they'll hold a reservation without a paid ticket, and how long any pricing they give you is valid are two quite different and unrelated things. I believe the way it usually works is that when OW announces a price increase, to be effective on a particular day in the very near future, you had better be ticketed or very deep in the throes of the process when that day rolls around. OW seems to change prices on the 1st or 15th of a month, so Nov 27 is pretty safe, but no bets for December 1st.