I'm not sure if this helps, but for me; the registration page appeared as if my playtest was no longer scheduled, but it was because it's currently ongoing. If you are on a PC, check your EA launcher again. Mine was displayed there even though the registration website was acting as if my playtest session was over. The playtest should be in your library for download. If you're on a console then I unfortunately can't help there.
If none of this helps, then pester EA on social media lol, I want to say there was a limit to the number of players allowed into the playtest, but I can't be sure of it.
I'm on pc and still nothing in my library. I feel like they would limit the emails they sent out for registration rather than the amount of codes/playtests, that just doesn't seem logical.
