Yes, you can use and edit titles or menus in Studio 16 and Avid Studio that were created in previous Studio versions.
If the previous version (Studio 14/15 for example) was already installed when Studio 16 and Avid Studio was installed, the titles or menus should be stored here:
C:\Users\Public\Documents\Pinnacle\Content\Titles\My Titles (Menus\My Menus, etc.)
If Studio 16 and Avid Studio was installed on the system first, the titles or menus should be stored here:
Avid Studio Users - C:\Users\Public\Documents\Avid\Content\Titles\My Titles (Menus\My Menus, etc.)
Pinnacle Studio 16.0.0.75- C:\Users\Public\Documents\Avid\Content\Titles\My Titles (Menus\My Menus, etc.)
Pinnacle Studio 16.0.1.98 or higher Users - C:\Users\Public\Documents\Pinnacle\Content\Titles\My Titles (Menus\My Menus, etc.)
Note: Put the background in the "Backgrounds" or "Backgrounds 16x9" folder and buttons in the "Buttons" folder
The Titles or Menus will then be detected, converted, and added to the Library.