International Women's Day was in orgins a socialist / trade union event. The first one was in New York in support of garment workers, in fact in February.
The growing communist movement in Europe / Russia adopted it and it was called International Working Women's Day.
that's why many TUs saw it as their day. Ironically in Russia it then turned into a sort of sentimental day like Mother's Day. Many women in communist Russia had to work, but as elsewhere then went home to do all the unpaid work in the home. So they were given a day of recognition, and at most got handed a rose. (I suppose from what had become the famous song of women's suffrage, Give Me Bread and Give Me Roses).
It was recognised or became a global day when the UN said that 8 March should be IWD each year. That was in 1975 - whether because of second wave feminism I dont know.
So in fact the history of the day is not exactly about autonomous women's organisation although the WLM tried to make it that.
But I very much doubt that either 70s feminists, let alone TU women in the early 1900s ever thought it would be coopted by big business to make money and tell women their sucess should be measured by how far you have made it in the capitalist world, despite being a woman. 
(Mother's Day is again a commercial event, in contrast to Mothering Sunday which is tied to the church calendar.)
I think we need to not worry about what someone else is doing, but think what can we do on that day. Whether leafleting or starting a hashtag or raising money for your local refuge or rape crisis centre.