I think it would   make sense to keep the old samples as the current built in vuforia unity, breakes stuff from old projects

by always attaching ARCamera to any camera.

https://forum.unity.com/threads/do-not-run-vufory-when-the-application-starts.498351/

For older project that dont need the latest Unity (are fine with 2017.1) and Vuforia and would like to keep the migration cost low.

Hello fabiosabr,

The Advanced Topics samples for Unity will be available on the Unity Asset Store very soon. I'll make an announcement on the forums when they are ready.

Thank you for your patience,

-Vuforia Support

When the Samples of Advanced Topics go avaible to the Unity ?

Hello ashot11AR,

Unfortunately, we do not keep downloads for old versions of the Vuforia samples or sdk.

Apologies for the inconvenience,

-Vuforia Support