Frustrated that nursery are teaching my son childish words for body parts

We’ve all heard the reasons why it’s best to use the actual names for body parts with kids - specifically, genitalia. (The kid whose uncle was touching her “cookie” always seems to be the one people bring up on Reddit.) So we’ve always said penis, testicles, anus, vulva, vagina etc with our kids. They’re not rude words, they’re just body part words, like elbow or skull or kidney.

Yet for some reason, my 4yo son has started referring to his penis as his “widgy”. Why? Because that’s what the grownups at nursery call it. FFS. To be clear, he’s always called it a penis, because we’ve always called it a penis. Because that’s what it’s fucking called. (Edit: they’re definitely saying widgy, not willy. His key worker said it in front of my husband.)

I’m probably unnecessarily irritated by this, but like, it’s literally recommended to parents for safeguarding reasons. Why would you take a kid who uses the actual word and correct him to a nonsense word??

Edit: thank you to everyone who has commented, including the people who didn’t agree - I appreciate all your opinions! I decided to email the nursery manager about my concerns, but I’m not asking for any specific action to be taken, I’ve just said I wanted to bring it to their attention and I will leave it to them to do as they see fit. I don’t want anyone to get in trouble, but since we are going to be using this nursery for years to come yet (my son is nearly ready for primary but my daughter is going to be attending from next year), I didn’t want to let it fester.