Interestingly, speaking to the girl at the white rock tells of how it's there to 'wish their rockets to fly safely.' Then she says '..what do you use [to wish]?', 'I use a wish tag to make it happen.' Now granted this is exactly the same as in the originals, but it would be cool if GF actually used it for a Jirachi event rather than just leaving it as a red herring.
If Jirachi is obtainable in OR/AS, it'll likely be as an event in my opinion. I just doubt that Jirachi will be available during normal gameplay given its history of being event-exclusive.