My FIL went to catholic school in the 1950s and we are a practicing Muslim family. He said that he learned the religion that they taught in school and then learned the Muslim faith at home. Back then, the catholic school was the best school in the area so it was inevitable that he would attend. We have discussed this possibility as well as the catholic school is really good in our area. We’d be ok if LO learned the religion as long as it was understood what religion we practice and follow. Have you talked to the school or the teachers? I’m sure there are others that maybe in a similar situation ? The Canadian catholic schools seem to be more open than some traditional catholic schools in the US.