Somewhere in all my reading I thought I read that they were demolishing some of the buildings. You can use this link
http://my.sfwmd.gov/ePermitting/PopulateLOVs.do?flag=1 to search for the Reedy Creek Improvement District construction permits. Generally speaking the
demolition permits are included in the Construction permits for existing structures or areas.
Here's a hint to help you search this site. The Hollywood Studios construction project is referred to as "H 1 Site Development". Be sure to remember that demolition plans are included in the Construction permits.
Disney is not required to reveal much information publicly about their construction plans, unlike other private/public entities, because they were granted special accommodations by the Florida State Legislature. Disney does have to publicly file permits for the South Florida Water Management district.
The Theme Park Tourist site, in an article dated May 16th, talks about how DHS is ramping up demolition. Of special note here would be the demolition of the massive Lights, Motors, Action stadium.
I believe that Disney generally does not "warn" people of fireworks testing because most people would hear that noise and associate it with fireworks. A building implosion is an entirely different matter,
if that's what is going on. Like I said, we won't be informed of Disney's Construction/Demolition plans. We will just have to wait to hear the boom and figure out if it was fireworks or a building.
~NM