You can’t upload a package to AUR. You only have a PKGBUILD in AUR. Everything in AUR has to obtain the package from a source.
If you read the PKGBUILD, the source is:
source=("https://downloads.exodus.com/releases/exodus-linux-x64-${pkgver}.zip"
"${pkgname}.svg"
"${pkgname}.desktop"
"LICENSE")
The package is pulled directly from the Exodus website to be built on your system.
So this is false information:
Also, you don’t have to just trust the person. You can just view the PKGBUILD and also read all of the AUR comments for your package.