I think the WI overestimates how many women are truly supportive of men who pretend to be women joining.
When the announcement was made, some of my own group spoke up saying that excluding then was 'a disappointing step' or ' really backwards '. At the time, I posted on here, saying I was upset that so many people had said so, but now, when I look back, it wasn't really 'so many ' at all, it was just a couple who were particularly vocal, and everyone else just said nothing.
I personally am delighted that my WI group will get to remain women only. And I won't be participating in any 'sisterhood' activities at all (though I might advertise them to all the men I know who are not pretend women, but who might fancy popping along anyway)