Is it possible to migrate Sharepoint 2016 and all it's databases from SQL SERVER2012 to AZURE?
Is it possible? Yes. 

Should you? Documentation says...


  Important edit: this is currently not officially supported for
  SharePoint Server, even for Azure-hosted farms. This is likely due to
  the 1-millisecond SharePoint -> SQL supportability requirement which
  Azure SQL Database doesn't &amp; won't guarantee. At the time of writing
  there's no plans to do so either, so please note that despite the fact
  this configuration by all accounts does work, this article is purely
  academic.


No.