My department has gone paperless and uses Moodle to provide all information to students in an electronic format. With a paper based syllabus the expectations were cast in stone (okay ink on paper). Now that we are on Moodle, we can change the syllabus whenever we want. Today, we had a staff member change the word count on an essay, that is due in two days, from a 1500 word maximum with a 10% allowance, whatever that means, to a strict 1500 word maximum. The students are confused and screaming about it. What type of departmental policy should be in place to prevent changes.
Fundamentally, I don't think this problem has to do with the shift to a paperless format. Even with a syllabus on paper, my experience has been that a professor may well change it, often for good reason (e.g., shifting to make room for an excellent guest speaker, extending a deadline on a lab that many people are having problems with).
I think that the real problem here is that the faculty member has made a last-minute change that makes life harder for the students. Student who thought they were done with the assignment have just discovered that they have more work to do, it may be interfering with their other plans, class or non-class, and it just plain doesn't feel fair. Perhaps a good policy for that would be that no assignment can be made more restrictive once it has "started"?
There is also a place where the electronic aspect can enflame or mitigate the issue, and that may also address your original question. Online documents offer the potential for making a "sneaky" change that is not announced directly to the students. That seems to me to be something that should definitely be prohibited, and might be handled automatically by having the system send an announcement to all of the students whenever a course document changes. I don't know Moodle, so I don't know how hard or easy it would be to set up automatic notification; even without automation, however, you could certainly regulate that all non-trivial changes must have a notification sent to students.
I agree with jakebeal that "online resources" is a red herring. The issue is simply that the instructor has made a last-minute change to the expectations for an assignment.
I think it's a pretty basic principle of teaching that expectations for assignments need to be provided to students in plenty of time for them to create the assignment. If expectations are to be changed after they are communicated to students:
There should be a compelling reason for the change. (I can't imagine a compelling reason for 1650 words to suddenly be unacceptable.)
Students should have a reasonable amount of time to take the changes into account.
Changes that may invalidate work that students are likely to have already done should be avoided if at all possible.
Students should be notified by some "push" method (email, announcement in class, etc).
However, I don't think that you need to turn this into a departmental policy. It sounds to me like you have one person who needs to be counseled about their teaching practices - take the matter up with that person. Imposing a department-wide policy for something that should be common sense is passive-agressive, wastes the time of those developing the policy, and places an unnecessary burden on everyone else who now has to check whether they are complying.
(I made the same point here.)