In tera i think it was different in EU and NA. in NA i think your progress was saved. in EU not. Those that pre-order had 2-3 days early access.
i think it was same for Aion, though i didnt play beta there.
i think it's standard practice for all games, not just f2p.
for some games they wipe after beta, and you dont keep char or anything. Sometimes you get early access to create characters; it was like that in Tera too. It was like a week or 2 downtime after beta, so you had early access to char creation first, and then access to game 2-3days before launch.
And i think they want to avoid wipe in OB, as that WILL annoy some people, and might make them quit, even though people should be aware it's a possibility; And im sure SE wanna keep as many players as possible
