Is that something you can do? I wouldn't have thought there previous license would be compatible with the BSL, and so distributing the software under the BSL wouldn't be possible?
A bunch of commercial software right now (cough I'm writing this on MacOS) uses BSD-licensed foundations.
Indeed it’s something of a spiritual successor to CDDL which was designed precisely for that purpose (although reliable sources also say it was designed to be GPL-incompatible, so that is literally a he-said/she-said case).