it was originally worn by george michael in the music video for wake me up before you go go, back in 1984. at the height of the aids crisis.
even before he came out as gay himself, he was a big proponent for gay rights and awareness of the aids crisis. not to mention the shirt was designed by katharine hammett, a designer known for her leftist political statements in her works. here’s a relevant snippet from her wikipedia page.
Hamnett has spoken out several times against the slogan’s use by prolife activists in the U.S. She wrote on her website, “It’s not about the anti-abortion lobby. The US anti-abortion lobby attempted to appropriate CHOOSE LIFE. We are taking it back and promoting its real meaning. Ours is authentic and I believe in a woman’s right to choose.”
so yeah, its not a pro life shirt, and the meaning has become heavily misconstrued over the years.