I have tested 2 different Board Manager packages containing a library with only Out-of-the-Box examples with same result:

Invalid library found in C:\Users\pippopluto\AppData\Local\Arduino15\packages\AMEL\hardware\samd\1.0.0\libraries\SME_basic

A quick discussion with @cmaglie may lead the issue is due to lack of source code because the library contains only specific examples in .ino form. This would make sense regarding how Arduino libraries are formalized.

Is it an issue or are we trying to use an IDE mechanism not planned for that?
If latter case, would it be possible and easy to allow Board Manager Packages to embed specific examples?
I think mainly about having a formalized 'examples' folder at package root, ie same level as also optional 'libraries' folder.

Thanks,

T.