So...

[JimN]

Parlophone (and "Calderstone Productions") release 50+ year-old (and hitherto unreleased) Beatle out-rakes and broadcast recordings to prevent them from being out of copyright...

Briefly, the much-vaunted extension of copyright in recordings only works for recordings which have actually been released.

For recordings which have never been released, the copyright limit is still "only" fifty years (and presumably must start from the day of recording, since there is no other legally-significant date in the history of an unreleased recording).

This being the case, all hope is not lost for the Rollercoaster tapes...

[iefje]

Good. This will then hopefully end the wealth of budget multiple CD sets by The Shadows and Cliff Richard & The Shadows, full of mediocre vinyl dubs and corrupted sound mixes, though quite a few CD's released until 2008 (before the copyright from the very first recordings had expired) also had these.
Good news too for the unreleased BBC radio session recordings!