Since I am not a lawyer, and definitely not a Trimble lawyer, and very definitely not YOUR lawyer, I can only offer some links and opinions.
Here’s the EULA for make: https://www.sketchup.com/license/b/sketchup-make
If you upload something to the warehouse, your content is now covered by the 3DWH terms of service: Terms of Use | 3D Warehouse
You pretty much have to hire a lawyer to answer any questions you have about your particular use case. This seems to be the American way, for better or for worse.
Trimble Connect is designed to give users more control over file ownership and access, if you have particular concerns about security and ownership you may want to investigate that instead of the 3DWH.
Marc