This will be long response for the benefit not only of OP, but others looking into the same issue. I'm going to somewhat disagree with every single other poster above and say you need evac coverage. After living in Beijing for 10 years, I've seen what happens when a foreigner (child) is hit by a car in a Beijing street. And a friend with a bad fall in Guilin that broke a femur. Etc etc. It happens in all the "on the beaten track" places, believe me. For the average healthy traveler, accidents are generally more of a worry than illness in China. Don't listen to anybody who tells you the normal Chinese hospital system is good--it is not and just negotiating the system is a nightmare. I've had first-hand experience on more than one occasion and that includes the Emergency Room. The expat hospitals don't have a lot of depth in their physicians and facilities for many specialties, so for some types of injuries/conditions, you'd have to use Chinese facilities and doctors and hope for the best. There are some decent doctors sprinkled around major cities, but finding them is a needle in a haystack exercise not easily done on short notice and in an emergency. Infection control in Chinese medical facilities is a crapshoot at best.
Having said that, you don't need to succumb to panic or overreaction. I will also agree that the insurance you are looking at for med evac isn't what you should be buying. That TravelEx thing is a piece of crap in what it provides for the money. I don't know how you did your research process, but first of all, it seems very very expensive for such a short trip, and especially if you already have decent BC/BS coverage that will work for non-evac medical expenses overseas. Second, nearly all evac policies will not necessarily evac you to "home" or anywhere you want--read the fine print and you'll see the language probably states something like "nearest suitable facility." And that interpretation will be up to the insurance/evac company. Depending where you incur a problem, it could be a bigger city in China, could be Hong Kong or Bangkok. But not automatically the USA. Cost of an evac from Beijing or Shanghai to USA is probably between $40-70K depending on whether it can be done on multiple seats on a commercial airliner, or dedicated medical airplane. Add another $10-20K from Chengdu, Hefei, Guilin. So a per person evac coverage of $100K is more than adequate for this sort of trip that doesn't include the Himalayas or far West.
I suggest you try to get coverage for less. First of all, start by looking at
www.medjetassist.com which is an evac membership program not an insurance plan. It's one of the only companies I know that will take you anywhere in the world you want to be evac'd, no questions asked--just need to require inpatient care. They have short term and annual single and family plans. Cheaper and better than what you are looking at now, and this company comes highly recommended. This will not overlap with your Blues coverage.
For more typical evac coverage that is bundled with travel medical and so will provide overlap that you personally don't seem to need, you might as well look for something either better or cheaper or both. If you only want coverage for this one trip for the next year, look at
www.worldnomads.com at a family plan. If you will be going on multiple international trips (each trip less than one month), look at
www.ihi.com look at "international-personal-travel" insurance, annual plan policy. Outstanding company and they set up coverages in the European mode by percentages not fixed $ limits. I'd choose them over any US-based insurance company for travel/evac. Of US-based companies, HTH Worldwide has one of the better reputations but I'm not familiar with the specifics of their travel insurance product.
I have found Squaremouth seems to leave out or not have in their database a lot of possible options, especially for international travel or expat medical types of insurances. Squaremouth is convenient but not the gospel. Also, one reason what you're looking at is so expensive is the trip cancellation part. If you can forgo the TC and related (baggage, etc.) fluffy stuff with its sundry loopholes, and rely on your regular homeowner's policy + common sense for property, you should find what you really need for cheaper.