The sentencing act means that as of 1st October 2026 (unless it changes again) all eligible prisoners will be released after serving 33% of their sentence in custody (previously 40%) or 50% for those convicted of more serious offences (previously 67%). But releases are being staggered depending on the length of sentence, so many will serve more than the minimum period with many not being released ahead of their existing release date.
I don't know the explicit details, but my very simple estimates are that the two individuals would have been expected to have been released around the autumn of 2027. As it stands they could now be released around June 2027, with tagging and additional supervision than they may have originally had.
This doesn't make it right by any means, but the difference in these cases is fairly marginal.
I do however think that this could have all been avoided if the eligibility excluded sex offenders, serious violence and those of high media interest.