the dancing is no longer conservative. I've played ballroom gigs for more than 10 years now in New Zealand. It's become a competitive sport with young and old participating in competitions of various grades with innovative dance routines. Many ballroom dancers also perform latin dances, and these moves are more provocative than conservative. I think they are only conservative in terms of wanting the correct tempi to dance to.
Hence us musicians have to be very careful to provide the correct music. The mood or flavour of the music is just as important as the correct tempo. Also the tempi for competition dancing isn't always the same as social dancing. I haven't played for ballroom dancers in other countries but I suspect these standard tempi could vary a bit in other places. Hope this helps...