The unconnected Output Port will not be handled as an unused pin.
The Bitstream setting of the unused pin Pulldown (Default) will not be applicable.
This port will behave as user I/O that is not driven.
Device reliability is not an issue with this usage, but a Floating/undriven state is not recommended.
Either delete these undriven ports in HDL, or handle it via Pullup/Pulldown externally.