Mine too..
Speaking as some one not in the air, my contract has the statement that i am "expected to work additional hours as necessary, for the good of the company".
Fair enough. That has been there for at least 9 years, and yes, i have worked more than my mandatory hours, but i've never been forced to work in another area, nor forced to stay on or to come in on my days off.
Yes, i've been asked to volunteer for other duties, extra hours, but never forced, and if i HAVE stayed on after time, or come in on off days, then i've been able to have that time back another day.
I don't think it is a macheavallian plot to make crew into all round dogsbodies. Just trying to align agreements company wide, with the fact that aviation is, sometimes unfortunately, an unpredictable beast susceptable to many factors outside an airlines control.