I'd suggest everyone interested visit this site:
Home | Safercar -- National Highway Traffic Safety Administration (NHTSA)
My guess is ETI sells many trailers in the USA and 'maybe' there was a complaint, insurance claim, lawsuit, or whatever and it 'got the attention' of the NHTSA.
Looks like everything is now electronic and companies ALL must comply with the process for OUR health and safety. I'm thankful to be able to enter the VINs of all our vehicles and will get email notification of any recalls.
If you think of all the possible things that could trigger a 'suspension' like a solar panel flying off, a cracked frame, etc. that would be reported by police reports, insurance claims etc. ETI would get notified and IF they were slow at responding, or simply didn't have the drawings, plans, schematics or whatever documentation not properly signed off by the appropriate "professional", delay in mail or processing ... all could result in a suspension.
I'd guess that ETI was not 'surprised' by the suspension but may have been struggling to comply with requests. I see the 2017 model introductions has not gone as smooth as they would like. Possibly delays in this NHTSA process could have an impact on their process?
You are welcome to your opinions about the government. Personally I am thankful the NHTSA agency is forcing manufacturers to make fair and timely recalls and making the process transparent to ALL of us on the website.