Most likely the OB will roll right through to the release. There aren't typically huge release dates for F2P games, they just kinda turn off the code requirement one day.
I made a video on the GC purchasing process:
To clarify. If you were invited to this test any GC that you purchase will be credited back to your account during OB, +20%.
Purchase 100 GC
Your account will have 120 GC (100 + 20%)
Reminder this is only for people that were invited to help test the system.