In most respects, release of the tape isn’t actually necessary.
All that is necessary is discussion in the campaign that such a secret tape exists. In fact, the status quo might actually be better in some respects.
I was thinking the same thing... maybe the LAT is pulling a rope-a-dope: Get the McCainiacs all riled up, then release some innocuous tape on Monday, leaving no time to challenge whether it was edited or not. Nothing to see here, move along...