Since Shopware 6.7.3.0 the language pack displays a warning, that it's recommended not to use it and that it will not work with 6.8.x anymore. Unfortunately the deinstallation of the language pack removes all translations included there (test with 6.7.4.0, with selection "Remove all data it even throws an exception).
The dev docs recommend this way https://developer.shopware.com/docs/resources/references/upgrades/core/translation/language-pack-migration.html. But not every customer is feeling comfortable being forced to use the command line. It is intended to activate / deactivate a language via the language itself. So why don't you add an install / uninstall routine in settings > language to process bin/console translation:install --locales it-IT linked to the switch's setting? Perhaps in addition whether the snippets should be installed / uninstalled?