Hi Tony!
This isn't a part of RStudio Package Manager yet, but I'd love to chat more about your expectations and goals for this work. If you're interested shoot me an email: sean@rstudio.com.
If you're short on time looking for alternatives, Mango offers a set of "validated packages" through their ValidR solution - a bit different from virus scanning all packages though.
There is also work underway by a collection of Pharma companies to create a list of validated packages - where validation is focused primarily on verifying a package's functions for correctness.
Both of these projects focus on carefully understanding the source code for a subset of R packages. They are not directly focused on automated scanning for security vulnerabilities, which as the blogpost you reference mentions is hard to do for an interactive language like R.
Best,
Sean