I don't make my kids hug or kiss anyone they don't want to. I was never forced to as a child because different experiences that my mother had growing up. I was always thankful that my mom never made me because I would go through phases of being shy.
Quite a few years ago now, my husband's family had a Christmas party and my husband's Aunt told my daughter to come give her a hug. My daughter looked at me timid and I told her she didn't have to do anything she didn't want to. So she didn't hug her and just said, "Merry Christmas". Later, my mother-in-law confronted me about how she thought this was rude and "It was just Aunt [name redacted]". This was an uncomfortable conversation since I don't like confrontation, but it needed to be said. It wasn't about undermining or embarrassing anyone, but educating. I told her that I would never force my children to be hugged or kissed by anyone even if that person is their Great Aunt because it's their body. I also mentioned how they don't know her very well because they don't remember seeing her at all. I don't know what changed my mother-in-law's mind for sure, but she no longer expects the grandkids to hug anyone that they don't want to.
The reason I have this rule is simply, I don't want my kids to be groomed for sexual abuse.