"IF" you really really really want to move up you have to be invited. I do not think NDSU really really really wants to move up..I am not sure there was an invite from CUSA...I have doubts that the MW is looking to add any school moving forward even if a couple schools leave. Neither the WAC or the MW has ever taken in a member directly from 1AA or FCS. This is not a starter league.
Were I in charge at NDSU I wouldn't jump at CUSA either but I think I would also recognize that better conferences expressed zero interest in NDSU during this latest shuffle..
If, maybe, your only option is CUSA now, waiting around for a better option might never be coming.