I think I just found another answer for this. It seems Windows Explorer will not read Wavelab RIFF INFO unless the Wavelab file also contains at least something in the BWF (or whether adding the BWF moves the RIFF to the spot in the file Explorer wants to see, I don’t know). Mac Finder doesn’t care either way (Mac Finder seems to always read the Wavelab RIFF Info, BWF or not).
The first picture is the metadata of a Wavelab file with RIFF INFO only. Windows Explorer won’t display the RIFF INFO in this file. The second picture is the metadata of a Wavelab file with the same RIFF INFO, but BWF added. Windows Explorer will read the RIFF INFO from that file.
The BWF metadata is also related to importing Wavelab wav files in Pro Tools. Pro Tools (with AES31/BWF prefs on, which I believe is the default) will say the file needs to be converted if it doesn’t contain the BWF. With the BWF, there’s no such message, and the file can be added directly to a Pro Tools session.