I have not noticed old styles being deleted but the one sneaky thing I have noticed is that RealTracks purchased in an add-on like the 49-pak will be repackaged as "NEW" in the following year's "202 NEW RealTracks for Band-in-a-Box"!

My long-time strategy is buy a cheap HDD for backup and simply copy your entire current BIAB and Realband installation to that drive BEFORE upgrading. Then, upgrade right over top of the original installation knowing you can always use the older one if you wish exactly as it was before.