I think its all the same. Gap coverage is to cover the potential gap in what a vehicle is worth, and what its financed for (I am reasonably sure you are aware of this but I am just making the statement as part of my explanation). Gap coverage can usually be purchased with the loan, or through your insurance company, and its the same coverage (they just may charge different prices for it).
Like, Financing gap coverage through a regular car dealer is one of their profit centers, and they tend to charge "a lot" for it. Getting a loan through a separate financial institution for a vehicle, many of them offer to add gap coverage to the loan for a fee.
One can normally contact their insurance company and see if they will offer gap coverage on the vehicle. If you put enough down, there usually isnt a gap, but if one is doing a minimum down type loan, there normally is.
Still, if Gap coverage was something this OP was expecting, Even if Tesla does not offer it, The time to investigate that / Ask for it is before doing the loan, so I still dont get the "wtf" nature of this first post.