I've been to two school reunions, one 25years & one 40years from graduating.
There was no obscene language, no drunkeness & no wild dancing & were both very enjoyable occasions.
The first time I went I was concerned someone would tackle me about 1975 as I had tried hard to put into practice the society's admonition to witness to my school friends in the years leading up to that date. Thankfully no one brought the subject up.
I would recommend going as the WT leaders are WRONG to suggest you should not go.
Ed