If you own a regular PSN account with a ps4 registered, that email should receive a beta invite if used to submit for beta, playable on a ps4 obiouvsly
A free account for ps3 owners? Square PR must be a fool giving free accounts instead of cash out
Also, even if ps3 users gets a free account, the ps4 account is paid separately form the ps3 one (should at least) as an entire different platform, like pc vs ps3 accounts.