yeah, when you reference an RCL during development it adds a composite file provider, one of the inner points to

~/.nuget/packages/foo/{{version}}/staticassets/bar

, the other to

./wwwroot/bar/

(may not be exactly these paths but close enough) When you publish your site they all end up in

./wwwroot/bar

and the composite provider isn't required as physical file provider handles both