I own a 2013 EC 950 that was actually manufactured in late 2012.
I had the entire front cap delaminate from the bottom ( the part just over the cab ). They completely removed the cap and replaced it at the factory. They also did some modifications for me gratis for my inconvenience.
My grey water and black water tanks also sit on the same styrofoam but not as loose as the video you took.
I've taken that camper all over the country, paved and dirt roads and have not had any tank or plumbing issues.
Now had I noticed that BEFORE I purchased the camper I would have the same concern as you. You might want to call EC and hear their explanation for their install.