I leave at 5.30 for daycare pickup. Now half my team leaves at 5.30

Daycare closes at 6.30 and it's forty minutes in traffic, so since February I've walked out at 5.30 and logged back in after she's asleep if something needs me. I didn't announce it. People noticed anyway. This month I count at least six people on my team leaving at the same time, several of them without kids. Work is getting done, deadlines are fine. My own manager has asked, half joking, whether I'm 'starting a trend'. Is this something I'm supposed to fix, or something I should say out loud is fine? Never had to think about what my leaving time signals before.