That's a good question.
The answer, I think, is that not only acts as a unit. I can't think of another adverb which can take not in this way.*
The regular form I didn't only lose all my money is also possible.
*Constructions with not + adverb are common when there is no verb, as in "Do you always go that way?" "Not always"; or "He finished the job, but not quickly". But when there is a verb, the negative normally goes to the verb in the usually way "I don't always go that way"; "He didn't finish quickly".
Edit: I have thought of one more example: not infrequently. But neither often nor frequently works this way.
How is one of those interrogative words that lets us ask a question, often with the auxiliary verb do:
How do we communicate?
How asks about the manner of something (here, communicating). By dropping the do, we can transform this question into a clause that stands for the manner of that something:
how we communicate
Manner is an abstract noun, and wherever we can use that noun in a sentence, we should be able to use the how clause in its place:
As the subject of a sentence:
The manner of our communication is important.
How we communicate is important.
As the object of a transitive verb:
I like the manner in which we communicate with each other.
I like how we communicate with each other.
As an objective complement:
He showed us the proper manner of communication.
He showed us how to communicate properly.
And, as in your sentence, as the object of a preposition:
The change is in the manner of our communication with each other.
The change is in how we communicate with each other.
The appearance of a particular preposition doesn't depend on the how clause, but rather on what word licenses that preposition, i.e., what preposition is idiomatic with the word. Change can take in. Talk, on the other hand, takes about. So it's no surprise that we say
Change in how we communicate.
and
Talk about how we communicate.
Best Answer
We really need more context. I suspect the cited text isn't really an "independent sentence". For example, perhaps it's one of several "bullet points" listed under some context-setting initial text, such as The Board of Trustees are agreed that...
...in which context subjunctive ...that the Directors be authorized [to blah blah] is perfectly okay, as is ...that the Directors are authorized [to blah blah].
Both verb forms represent "performative utterances", in that making the statement is equivalent to providing the authorization - same as, for example, I [hereby] promise to tell the truth.