I think that this probably cuts both ways. I have noticed an increasing habit of people cancelling plans at the last minute. I am thankful it hasn't happened to me but a I know so many friends who have had it happen on numerous occasions and appears to be a real habit amongst some people.
The 'can't be arsed' attitude to social engagements seems to be quite rife. The initial enthusiasm of a social plan, whilst still theoretical- often seems to turn to dust when the 'effort' of actually attending , (Getting dressed up, travelling etc) is upon them - and a same day cancellation accompanied by some unarguable excuse is produced.
The excuse 'du jour' is almost always 'COVID' . (after all, who can argue. ? Request a copy of the test ? State that you don't care if your social companion brings an often deadly virus to your gathering ? ) ...
I am not for one moment suggesting that your husbands COVID was fake and that you really couldn't be bothered to attend OP. I am suggesting that as this type of behaviour is so prevalent at the moment, that your cancellation last minute may have been the 'straw that broke the camels back' , if your former friend had suffered a number of these last minute cancellations prior to your genuine problem in attending - and like my friends, have decided to cut out of their friendship groups, those who would rather let them down rather than make an effort.
There are always two sides to a story though... and I am also imagining that anyone who has been through the expense, time and planning of a wedding - no matter how rushed - who still requires a 'hen' is probably fairly high maintenance and demanding.