I sincerely hope that [all foreigners | all non-Chinese | everyone] in this group can have a happy and healthy Chinese New Year in China.

This sentence is grammatically correct, but the word “foreigners” sounds unwelcoming. I’m sure all Westerners who speak Chinese have grown accustomed to being called “外国人” and “老外” while they’re in China, but in the US, we rarely call people “foreigners” unless we want to emphasize that they are “outsiders” and “don’t belong here.”

Interestingly, whenever I call a Chinese person living in the US a “老外”, they always seem very uncomfortable to be on the receiving end of this label. In fact, even though they, themselves, are actually foreigners in the US, they still call the local people “老外”. I guess “老外” really means “Westerner,” not foreigner. 🙄

I hope all people on this planet have no conflict and live together peacefully.

Without “all” it means “some,” i.e. if just two people did this, it would satisfy your hope.