Do you own it? Then just add it. Or import it from that Discogs link. There’s a handy importer script available.
There is a very small number of paid staff who work at MusicBrainz.
I’m not sure if us voluteers outnumber them 5000 to 1. Or maybe it’s closer to 50,000 to one?
Anyway, the vast majority of adding info to the database is done by us volunteers.
It could be that one of us will see the missing Hendrix Release you point at and then add it.
Or it could be that the surest way to get it added to MusicBrainz is to add it yourself.
If you take this approach then please bring any questions/obstacles/deal-killers to these forums and other volunteers will show you where to look to learn how editting works. There are some volunteers here who are very skilled at helping new editors progress.
Also see How to Add a Release - MusicBrainz
Thanks for the responses. If no one jumps on it, I’ll try running that import script later. How hard could it be?
Best way to learn anything is make a mess and break everything. We will then help you fix the mess.