No, it would just work on the list of files you give it (like loudgain [options] file1 file2 file3 …).
But you can use the included rgbpm bash script which allows recursive tagging, assuming there is one album per (sub-)folder. I use this myself every day.
So assume you have a folder ~/Music/todo and subfolders like this:
/home/rafael/Music/todo/
└── ZZ Top
├── ZZ Top - Afterburner (1985 album, DE)
│ ├── cover.jpg
│ ├── ZZ Top - Can't Stop Rockin'.flac
│ ├── ZZ Top - Delirious.flac
│ ├── ZZ Top - Dipping Low (In the Lap of Luxury).flac
│ ├── ZZ Top - I Got the Message.flac
│ ├── ZZ Top - Planet of Women.flac
│ ├── ZZ Top - Rough Boy.flac
│ ├── ZZ Top - Sleeping Bag.flac
│ ├── ZZ Top - Stages.flac
│ ├── ZZ Top - Velcro Fly.flac
│ └── ZZ Top - Woke Up With Wood.flac
├── ZZ Top - Antenna (1994 album, GB)
│ ├── cover.jpg
│ ├── ZZ Top - Antenna Head.flac
│ ├── ZZ Top - Breakaway.flac
│ ├── ZZ Top - Cherry Red.flac
│ ├── ZZ Top - Cover Your Rig.flac
│ ├── ZZ Top - Deal Goin' Down.flac
│ ├── ZZ Top - Everything.flac
│ ├── ZZ Top - Fuzzbox Voodoo.flac
│ ├── ZZ Top - Girl in a T-Shirt.flac
│ ├── ZZ Top - Lizard Life.flac
│ ├── ZZ Top - PCH.flac
│ ├── ZZ Top - Pincushion.flac
│ └── ZZ Top - World of Swirl.flac
...
you just do rgbpm ~/Music/todo/ and it’ll work through all folders recursively. :-)
rgbpm is just a bash script, you can modify it to your heart’s content. Or, better, make a copy (maybe "my-rgbpm") and modify that, maybe just to calculate the track gain.
Hope this helps.