Nuendo's "Open In Wavelab" doesn't open 5.1-files

Thanks for all the clarification. I guess I always have used WL as a two channel/two track DAW designed for things like mastering and restoration (this is what I use it for) and I did my multichannel/multi-track work in Samplitude. One question that has NOT been answered is what are these files for? Is this for surround sound like 5.1 and 7.1 and Dolby Atmos or are these music files with different instruments on each track? Just curious. I am having difficulties figuring out why you would not do your multichannel work in Cubase or Nuendo or Samplitude (DAWs designed for multichannel/multi-track work) and then do your final “mastering” in WL. Is it a work flow problem or ??? What ever the reason it seems like it has taken a very long time to implement what people want in WL. Thanks in advance for the information.