Elise Zhang has not taken any sort of public position on the Hong Kong protests at all. Someone living in China and celebrating their national holiday while stating they love their homeland is not the same thing as taking a position on every policy and action of said country.
I celebrate July 4th and love America. That does not mean that I believe that America can do no wrong, or that I believe we are on the right end of every decision. I have taken to the streets and protested the actions of our leadership - does this disqualify me from loving America and celebrating it for the good parts?
For example, create a replica of their Lady Liberty and put it on the roof of the conference center or nearby hotel:
https://news.yahoo.com/protesters-erect-lady-liberty-statue-...
Or recreate "FREE HK" in neon lights and display somewhere prominent near Blizzcon:
https://s.yimg.com/uu/api/res/1.2/di1vjiAhE.3d29i_PNSPng--~B...
Basically, ping them back, let them know the outside world is getting their message and supporting them.
True, but also be prepared to be searched. If security can't legally search people, given the size of the event, they will very likely have police to patrol and do random checks "in case of terrorism", so hide your HK shirts, signs etc. because they would almost surely be confiscated for "inciting violence". If Blizzard fears any negative demonstration, they'll probably use every means for painting those supporting HK protests as violent disruptors and have police arresting them.
Edit: You can be banned from airlines since they are privately owned, but not airports since they are publicly owned.
You can also watch Winnie the Pooh cartoons on Chinese streaming services.