It depends on what and how much is being asked.
As you say, there's no predicting what will get asked once the whole world can poke at the beast. Rather than having a fixed plan to do updates on set timescale (which may end up being too long or too short), we prefer to acknowledge that something will probably need to be done, and respond as appropriate.
The aim is for everyone to play happily, so things that get in the way of that need to be ironed out as soon as possible. But some FAQ are more critical than others, and so we'd attend to them in priority order.
Experience suggests that there will be an initial group of FAQ when the games arrive, and then a fairly quick tailing off once people get used to things. So we expect to need to allocate more time around the release, and less as it goes on.