Very doubtful. In my personal experience I have found that emulsion binds/sticks and eventually weakens over long-term storage (I have had Velvia 50 and 100F in deep freeze since 1997 as an experiment). When loaded, the film commonly jams — at worse, drive torque can rip a bonded emulsion. This is not endemic to just Velvia, but many films, including Ilford Delta 100, 400, T Max 100 and 400, Provia 100 and roll film (because of the inclusion of paper backing there can be absorbtion of moisture into the roll if improper acclimatisation procedures are not followed from deep freeze to ambient room temperature). Realistically 5 to 6 years of storage and periodic removal into ambient temperatures is the best practice.

The remaining Velvia emulsions may be around for a few years yet, but the E6 process required to bring the images to life is diminishing in availability, save for home users. This in my eyes is the major threat, not the availability of E6 films. Once the process goes, demand for E6 film will I imagine drop very sharply and no amount of hording or insurance against "discontinuance" will reverse the problem. Summary: use Velvia now while E6 processing is reasonably easy to obtain and enjoy the results.