I had the same experience. Our pastor is usually really good at following the rubrics but we had kids and teens, mixed genders. He said it was to recognize the Jr. Catholic Daughters and Columbian Squires. But we had all male altar servers last night and this afternoon. And wonderful homilies.
From the GIRM:
The official version of the GIRM is the Latin. In Latin, this passage uses “veri selecti” for “chosen men”. This word “veri” means an adult male, not ‘man’ as in mankind.
The USCCB a few years back approved a proposal to ask the Holy See for a change to the rubrics allowing women and children to be included. The change was never approved by the Holy See so the GRIM should be followed “as written” until such a change is approved.
According to this website,
catholic-forum.com/forums/printthread.php?t=73, this is particularly significant for two reasons. First, the USCCB intended to seek permission to change the rubric, which acknowledges that they can’t change it without permission and secondly, the fact that they needed to propose a change at all means that they acknowledge that the current rubric is for men only.