Check out Q8/9/10 in the MPL FAQ: https://www.mozilla.org/en-US/MPL/2.0/FAQ/

I don't believe the MPL requires the ability to re-link; this is one of the reasons I chose it over the LGPL.

(My intentions are to promote development of the libfive by require changes to the library itself to be shared, while not limiting commercial use / distribution / embedding into a larger application; there is at least one commercial CAD company using libfive as a component in their application)