Please let me join this very interesting discussion of the theme, too.
Reading all the responses to the original question I have got so far,
my wondering is whether all of them take account of the following
idea:

"... A manufacturer of drill bits may think that the customer needs a
drill bit, but what the customer really needs is a hole. These sellers
may suffer from "marketing myopia." They are so taken with their
products that they focus only on existing wants and lose sight of
underlying customer needs. They forget that a physical product is only
a tool to solve a consumer problem. These sellers have trouble if a
new product comes along that serves the need better or less
expensively..." [Kotler, P. & Armstrong, G. (1993). Marketing: An
introduction (pp. 4-5). New Jersey: Prentice Hall].

Considering this quotation, my opinion is that communication is the
most, most important of all the three important functions:
preservation, research and communication. In other words, each of the
other two exists just to help communication.

Then, even communication is just a means to serve people (whether
actual visitor or potential audience) who need some knowledge. In my
view, people visit museums to get some information which springs from
various sorts of media (i.e. audio-visual, replicas, hands-on, text,
and so forth as well as authentic objects). What do you think of it?

Thanks anyway for your attention to my brief note.

Ken