Most fundamentally fundamental issue...
Why is to deemed reasonable to re-write history? Correcting errors is one thing, but deleting facts is another.
If I have a customer who pays me money, I'm required to keep records for 7(?) years anyway. But our relationship is a fact. They can't pretend that it never happened. If they gave me a testimonial which was published in the local paper, am I required to track down every extant copy and cut the advert out with scissors? If I included a list of customers in the annual accounts, do I have to get them back from Companies House and edit them?
There is probably a case for not publishing data for x years, but (to quote the Grauniad) 'facts are sacred'. Lock sensitive medical data away for 100 years, but don't delete it, it could be useful in the future, tracing inherited diseases. Criminal convictions? Mark them as spent on the PNC, and lock them away. But they've been published in the local paper. How will those records be removed?