Does Bootcamp still result in a hybrid MBR/GPT situation?
Based on the information in your question, Windows 10 UEFI boots on your model Mac. Most users use the Boot Camp Assistant to install Windows 10. You do not have to use the Boot Camp Assistant, however the easiest way to download the Windows Support Software (the drivers) is to use the Boot Camp Assistant. Once you have the Windows Support Software, you can install using a flash drive if you wish. 


  You can use the Boot Camp Assistant to download the Windows Support Software without actually creating a partition and installing Windows.


You will not need hybrid partitioning to run Windows 10 on your Mac. This is true whether or not you use the Boot Camp Assistant to install.