Since version 2.2, static-content:deploy for a theme will generate themes not specified using the --theme flag.
So before in 2.1.x I would generate a theme for 3 languages and get exactly 3 themes. Now I get 12.
Is there a setting I am missing or is it a new "feature"?
The command I am running it with is:
magento setup:static-content:deploy --theme My/theme de_DE en_US fr_FR -f