In terms of using the data for initial training of a machine learning model, it is a very good idea, because Google Translate produces exceptional results, which will give yo very good ideas about how to go about building and improving your machine learning model and save you time in the long run.
As for releasing the dataset to the public, Google has a website with information and from my understanding they just want attribution.
However, if you are dumping a dataset larger than 500k characters, because that is the tier of free usage per month, it seems to be more likely to be a violation of their Acceptable Use Policy that does not allow us
to disable, interfere with or circumvent any aspect of the Services.
From my reading of the website Google does not provide any direct answer.
But they even have a special form for asking about publishing Google Cloud Translation so I encourage using that form to ask them directly.