What you’re looking for is a very common request, but at the moment Studio Pro doesn’t offer a single “one button → translate into all languages” feature.
Out of the box, Mendix works with a one source language → one target language per run model, whether you use Batch Translate or the AI-based Translation Generator (Maia).
If your real goal is to translate many languages in one go (for example adding 10 new languages at once), the most scalable and commonly used approach is to work outside Studio Pro:
This gives you the “translate everything at once” experience, just not as a single button inside Studio Pro itself.