I look at the Recording in question:
I can identify on that page three releases where this is track 10 on a CD.
And as two of those releases are a multi-CD edition where CD1 has 12 tracks then that data tells me there may well be a digital media release making it track 22.
As @outsidecontext says - this is harmless data. Minimal but useful.
I have seen some releases where the ONLY data is something that says “track 4” and it did allow me to confirm it was a match to my release that was also a “track 4” on the CD I had in hand.
For rare CDs this is useful data. The blank entry is less useful as it literally tells me nothing.