My experience is that at least some multinationals have staff that do nothing but Emergency Response Planning (ERP), Diaster Recovery Planning (DRP), and Business Continuity Planning (BCP). And having evacuation as an emergency response is not unusual; for instance, in Tokyo, which is just waiting on the next great earthquake, I believe that evacuation procedures are indeed considered and in place for some companies. (I wouldn't be surprised to find that generally such company plans are to evacuate within Japan for Tokyo earthquake scenarios.) Certainly, the civil authorities in Japan encourage planning; take a look at this recent symposium and this one also. (I notice that my drift could make it appear as the city of Tokyo's internal planning is to evacuate within Japan for earthquakes; I believe that it is instead the city's plan to evacuate residents to local aggregation points if evacuation procedures are activated (see page 26 for instance of the Tokyo Earthquake Handbook.) In fact, as Kobe in the Great Hanshin earthquake demonstrated, residents have a critical role in search and rescue, and transportation difficulties in a highly urban and industrialized area in the event of an earthquake are hard to overestimate. (Kobe also, unfortunately, showed many limitations with respect to planning, plan integration, and particularly lack of testing, especially with fire suppression systems -- somewhat of a surprise considering how much experience Japan has with massive fires in the 1923 Kanto earthquake as well as of course the great firebombing of Tokyo in WWII.))
You cannot do planning once an emergency begins; that's when you execute your procedures that you have in place (and usually there are still decisions to make even with the best plans in place.) Planning comes beforehand. Drawing up scenarios is a big part of your planning. If you were a planner in Taiwan right now, I believe that "Incipient War" would be a scenario where you would be well served to make sure your planning and procedures were up to date.
ERP can help alleviate losses in bad times, including human, financial, and reputational losses. Successfully done, it can make the best out of bad situations. Even minimally done, it certainly can help make things better.
Some of the more forward-looking companies are in the early stages of adopting this mind-set right now. It is extremely low key. Taiwan is a small island. Secrets don't keep well here.