I can see no reason why we should not call it Christmas, people I know of different nationalities don't mind either.
I find it is is generally middle class, woke, do gooders who shout about inclusion. My partner is West Indian and he celebrates Christmas.
The more the merrier, when divali was celebrated, I have heard of parents who celebrate by sending in sweets for all children in their children's class in school.
I find the trend for not saying Christmas divisive, and gives those thugs who stand outside hotels draped in flags, being vile to immigrants housed there,an excuse to say shout the abuse they do.