Hey there again - I just read your introductory post. I apologize, in my first response I assumed your husband was all done with treatment. It sounds like he may be needing chemo/radiation in the near future. All in all, most everything in my initial post still applies. Given that your husband is on an NG (nasogastric) tube - it may be that the MBS will reveal that he's swallowing well enough now to have it removed sooner rather than later - the NG tube can be pretty uncomfortable so they tend to remove that faster than the feeding tubes that are inserted into the stomach through the abdomen.
The process to return to eating, IF a feeding tube is necessary during chemo/radiation, can be tough because the muscles weaken quickly when not in normal use, the mouth can get very sore from the radiation and the sense of taste is impaired by radiation - so these issues may be ahead of him to one degree or another.

Looking at taking one step at a time - do the MBSS, let's hope he can get back to eating/drinking well before he starts treatment and keep doing so throughout treatment.
If not, he may need the more long-term feeding tube that is inserted into the stomach to get him through treatment and then have another MBSS later and work on getting the swallow back then.

Hope some of this info helps - in the mean time practicing swallowing by swallowing saliva and doing the oral motor exercises is key to keeping things moving!