I did this recently. I bought an album off iTunes and Apple Music fucked my library up so I had to revert to a backup which happened to be before I backed up that album. That album is no longer available for my region, according to iTunes, and iTunes/Apple support has been unhelpful in completely ignoring all my support tickets to ask how I can download a copy of this album I paid for.
Fuck it. I downloaded the album from less than legal ways. I did pay for the album, after all.