I understand what you are saying, growstuff - I just don't agree on the principle.
Value judgements about what is 'quite well-off' are insidious, and lead to all sorts of unfair and unjust outcomes. People make plans based on what they are led to expect, and to change that without notice is wrong, as is to make retrospective decisions about who is entitled to something that everyone has paid for.
If someone had planned to spend their twilight years in a yurt eating sausages, that is their right, and their needs are no more or less important than those of anyone else. As for whether they have husbands - that is irrelevant if they have paid into a pension in their own right!
The over-riding principle is that a decision was made to save billions by cutting the pensions of a group of women who had entered the workplace at a time when sex-discrimination was legal, and continued in various forms over the years. A further decision was made not to contact these women and let them know of the changes. some (including you) became aware of the changes, but others did not, and it is not for anyone else to decide whether or not they 'should have' done anything - the onus, IMO was on those making the changes to make them known.
By definition, the women were paying NI - a note could therefore have been attached to a p45, or there are other ways that they could have been told that were not limited to articles in newspapers that many of them did not read.