Frankly, same holds for gzip. I've been planning to relicense bzip3 with the more permissive LGPLv3.
gzip has BSD-licensed compatible alternatives already. It's doubtful the same attention would be given to bzip3; chicken-and-egg scenario there. Plus the lingering question of "Why not zstd?"
Gzip is just a frontend for zlib, which is BSD(ish).