Missing entire purchased albums with no option to redownload.

See if they are hidden:

1. Open the Apple Music app or the Apple TV app.
2. On a Mac, in the menu bar at the top of your computer, choose Account > Account Settings.
3. If prompted, sign in to your Apple Account.
4. Scroll down and look for Hidden Purchases or Hidden Items. Click Manage.

Purchased music should be showing in Music > Account > Purchased. If it is showing contact Apple Support: Official Apple Support

If it's not showing it may have been purchased with another Apple Account.

"Missing entire purchased albums with no option to redownload.: Greetings, Recently with the added updates to the IOS and Mac, I realized I was missing more than one albums that I had purchased and there is no redownload option. The entire album and songs are gone from my data and will not let me redownload them.[...]"

-------

Purchased Items Missing:

IF it is not seen in the iTunes Store, then it has likely been removed from their Library. Sometimes, Apple removed items from their library, and they never becomes accessible again. This all comes down to licensing between Apple and the Music Studio --something you would have agreed to upon opening an Apple Account.