You could use foobar2000 player to convert WavPack to FLAC.

There are a couple of not-so-common audio formats that WavPack supports but FLAC does not: DSD and 32-bit floating-point.

• foo_verifier, verify all files. (Re-encoding will produce "valid" files; if something is corrupted, I want to know, not to destroy evidence.
• foobar2000 to convert to identical directory structure
• foobar2000 with foo_bitcompare. (But first, check that you have the same number of files, same number of samples, etc.)
• Delete old. Again, using foobar2000
• Search old structure for WavPack files to make sure there are no-one left that weren't caught and indexed
• If you didn't copy "other" files, now it is time to merge.

Many moons ago (about 15-16 years ago) I had the option of choosing between WavPack, Flac, and APE (Monkey's Audio) and for some inexplicable reason chose WavPack. There was a discussion on Hydrogen audio in 2004-5 about the pros and cons of the various formats.

At that time I never envisioned portable media players being able to play lossless except for ALAC on Apple's iPod. Now I was just trying to stick to the same lossless format I ripped everything else with 15 years ago. I guess now I will have to convert to FLAC if I want to be able to carry my file on a portable music player (like the Fiio X3 Pro) or play them on media players like the Aune X5s.

Ironically, as a twisting ending, Wavpack or [insert  other obscure audio format here] will certainly be around in 10-15 years, and still playable on smart phones or what-have-you; whilst portable DAPs - save possibly for the odd high-end, premium, niche one - which seems to be already the de facto right now - will not!

I like WavPack. Nothing wrong about it as long as you have something compatible for playback ...

If you are tight on disk space, then converting and then deleting could be an issue, but otherwise ..
So, using foobar2000, I'd do the following steps (lots of overnight tasks here):

• foo_verifier, verify all files. (Re-encoding will produce "valid" files; if something is corrupted, I want to know, not to destroy evidence.
• foobar2000 to convert to identical directory structure
• foobar2000 with foo_bitcompare. (But first, check that you have the same number of files, same number of samples, etc.)
• Delete old. Again, using foobar2000
• Search old structure for WavPack files to make sure there are no-one left that weren't caught and indexed
• If you didn't copy "other" files, now it is time to merge.

1. I cant find a portable player that can recognize WavPack.
 

Foobar2000 app on android and iOS can play wavpack and also read replay gain tags.