What are you referring with that 2.0.1-preview? I could find any related package that would fit that description.
Latest SRP release is 1.1.5-preview (available through Package Manager on 2018.2b2). Latest PP Stack is 2.0.5-preview (also available through Package Manager)
It is strange. I downloaded it from Package Manager as you can see in screenshot above. Maybe this is a bug with PM and i got access to internal stuff.
I will write about it on PM forum theme.
Changing the registry to staging has been mentioned in the past on these forums. But I dont think we really know what the state of any of the packages on staging is, especially since pipeline version numbers on github do not resemble the 2.x.x versions you have got.
At the moment those wanting to try the very latest render pipeline stuff have tended to be using a github version, where it is at least clear exactly what version/updates are included. As of a day or two ago the github master branch of HD pipeline was still working on the publicly available 2018.2 betas, but at some point it is likely to stop working with public betas again, so now is a good time to try it.
An official comment from unity about the state of packages on the packages staging server might be useful, since these extra layers of confusion are not helping matters in am era that is already packed with great change.