Yes there have been some knowledge of some very holy and modest women have worn Tefillin.
Here is the difference between them and the psycho feminists of today who insist on doing it.
The holy and modest women would do it in private. Between them and Hashem. But the minute that a woman does it for "show", does it for the "look at me, look at what I am doing", it becomes a travesty. There is no mitzvah in it.
Another difference is the the holy women who have done it in private and the feminist who do it today is that the modest women were religious. They followed the other mitzvot. The modern day feminist do NOT. They intermarry, they eat whatever, they wear pants, they do whatever they want on Shabbat without regard to any of the melachot.
Therefore, they do not put onTefillin for any holy purpose. In fact, quite the opposite. They do it to be against society, they do it to fulfill childish desires, to be seen by others, to provoke Orthodox men. They do not keep any commandments (which makes them hypocrites) and worst of all, they do it to make Israel look bad. To make Israel look like Iran or Saudi Arabia suppressing women, so in fact, they are doing a Chillul Hashem.
We must not allow it. I don't think it will catch on in the Orthodox world. If Orthodox women do it, it is privately but I would not DARE do such a thing.