A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 20 June 2015
Can i refill my Provinces during Dynasty Phase, after recruiting a card, or only during Action Phase?
You have the ability, "Open: If you have fewer Provinces than one other player, then a number of times per turn equal to the difference (now), you may refill one of your Provinces face-up."
Jon Palmer (rules official), 20 June 2015
Can i refill my Provinces during Dynasty Phase, after recruiting a card, or only during Action Phase?
You have the ability, "Open: If you have fewer Provinces than one other player, then a number of times per turn equal to the difference (now), you may refill one of your Provinces face-up."
Coronation Festival's granted ability is taken as an Open action, and its effects last for the remainder of the turn. Therefore, it does not matter when the province is refilled - it can be the action phase (from resolving an event), the battle phase (from Recruiting a Reserve Personality) or the Dynasty phase (from Recruiting or Discarding) - the effect will still occur.