So I have been developing a board on SkiDL and the netlist importing works perfectly on PCBNew, but I was wondering if it could be imported into other software as well, especially OrCad.
At the minimum you would need a subroutine that generates a netlist file in the OrCad format. For KiCad, a similar netlist generator is in the skidl/tools/kicad.py file. You will have to associate an OrCad footprint for each schematic part using the footprint parameter.
KiCad supports OrCad netlist generation (fair warning I have never tried it) but in theory (so 50/50 here) you could use KiCad as an intermediate. The reality is that if you generate a standard SPICE compliant netlist and have all the devices in your OrCad library then you should be good to import any netlist. How easy Cadance wants to make that process be is outside the scope of this discussion.