The most qualified person to be teaching our ASL classes is our deaf instructor who has been teaching with this school for ~25 years. After all this time, they will not employ him full time.
This sounds like he is not a professor but a contracted adjunct professor. They're usually contracted by the semester and never guaranteed a renewal and same course load.
On top of that, this semester they began revamping the entire degree without any type of communication with him.
Not that unusual, that probably being handled by Department Head, the Dean and a committee at the University. Considering the low rank of non-full time adjunct professor would be so low on totem and likely would not be consulted.
He can't call them, he's deaf.
Not true, TTY relay services are widely available for free.
is only giving us enough of an answer to placate is, ie 'oh we are more than willing to talk to him.'
There's nothing wrong with this. I would be shocked if any Department head would have a discussion with a student about an instructor.
If he goes in for a meeting in person, there are no interpreters - even for official staff meetings. He has to rely on his ability to lip read.
Certification means very little here, its not like any sort of professional license to correctly practice sign. It is sounds like they attempted to provide an accommodation but not to his satisfaction. Without more details of that issues it is hard whether rights have been violated.
He's been teaching most of the ASL courses for many years, but suddenly he is down to one.
The department is reshuffling and redesigning the program. Adjuncts typically have their course load during and after such events.
They've completely gotten rid of some because this hearing woman didn't want to teach them.
This again sounds like a department reshuffling courses around. Other factor may have been at play like low participation or not enough registering for the courses. The other individual may be at fault or not. The instructor's hearing issue may be the reason or not.