Hi Alena thanks for posting in the community! 

1) Inviting the user to another team account will remove access to documents shared by the current team but they will retain all of the documents that they created. 
2) Sharing permissions are tied to an email address so if the account is not deleted and re-created there should be no issue accessing previously shared documents. 
3) The user will be separated from the original Team Account which removes their license. As such the user will have to join the new account and be granted a license. 

Hope this answers your questions please let me know if you need any other information! 

Nico

That is all the documents created by the user will be transferred to the new account together with the user? And if you have a new license these documents can be edited?

And 1 and 2 points contradict each other.

"Inviting the user to another team account will remove access to documents shared by the current team"
and this "Sharing permissions are tied to an email address ... there should be no issue accessing previously shared documents."

Can you explain? When transferring a user to another team will access to previously provided documents remain in the previous team?

Thanks for following-up Alena and apologies for the confusion. 

The documents created by the user will remain in their account and will be editable once a new license is granted (free accounts have limitations). 

To clarify I was referring to the documents shared at the account level (with the whole team) in point 1. These won't be accessible by the user once they change teams but any document that was individually shared with their account will remain accessible. 

Does this make sense? 

Yes thanks for the clarification.