The snapshot 20w06a is missing from the Launcher, on Mac at least.
MCL-17055
20w06a Missing From Changelog
Resolved
Won't Fix
0
MCL-17055
The snapshot 20w06a is missing from the Launcher, on Mac at least.
How peculiar! For me it shows up fine. Considering it's over a year ago and not an official release we won't look into this much more. If you want to read the note you can find it here too:
https://www.minecraft.net/en-us/article/minecraft-snapshot-20w06a