The Content Translation tool provides already mechanisms to adjust how much the tool is exposed to different members of the wikipedia community:

• Translation limits allow communities to indicate how much users need to modify the initial machine translation to be able to publish, based on the machine translation quality provided for their language.
• Machine translation services can be adjusted to provide the best option a the default for users.
• Limiting publishing to specific groups.
• Limits to quick translations (in-development as per T331023) to prevent abuse during contests and events.

I think we may need to be careful with restricting the tool more before considering the impact of the above adjustments. Some considerations:
With the current approach, newcomers acting in good-faith have a way to use the tool and share the published results under their user namespace for the community to determine whether they are good or provide feedback that helps newcomers to become more experienced editors. If we prevent them form even accessing the tool, we provide them with no path forward eve if they are really able to make a good contribution.

The other article creation tools (such as Visual editor or Wikitext editor) are available for them to create content without any additional limitation. We'll be redirectign users to use those tools where data suggests that they are more likely to be reverted when creating a new article.