Translation behavior depends on strategy set in Stores -> Configuration -> Advanced -> Developer -> JavaScript Setting -> Translation Strategy.
Take a look at full explanation here: What is the Translation Strategy
However, both strategies rely on regex pattern for replacing/collecting translatable strings. So the problem here is that string does not match the pattern.
So the only solution I see, without overriding rules.js, is to add the pattern for gathering translation files. You can do it from your module's di.xml like:
<type name="Magento\Translation\Model\Js\Config">
<arguments>
<argument name="patterns" xsi:type="array">
<item name="custom_pattern" xsi:type="string">~regex-pattern~</item>
</argument>
</arguments>
</type>See existing patterns here: https://github.com/magento/magento2/blob/develop/app/code/Magento/Translation/etc/di.xml#L63
