Hi again Jean,
I followed the link you sent and, yes, as you said, the instructor is using the 2.6.1 version of Painter. It is possible that since then some resources from the shelf were changed and reworked in order to optimize them.
You should access to earlier versions of Substance Painter however. If you log in to your account on the website, then go to Licenses, find Substance Painter 2, then click on All Builds, you'd be able to download the version that the instructor is using.
You can also just use the current map in the roughness channel, even if it doesn't have all the parameters, I suppose it should do just for training purposes.