Had a V class seat on IAH-SFO on 8/17 turn into R around 7pm on 8/14. Any explanation?

(I am Gold Elite, and expected EUA to run last night around midnight).

My guesses are:
1. I was manually upgraded due to a full coach cabin (doubtful, ITN shows Y9)
2. EUA now runs more frequently, including every time Revenue Management releases more R
3. EUA runs 72 hours prior to flight, not around midnight as it used to
4. I shouldn't ask and just be thankful for the upgrade.