Software Collections aren't "supported" in the same fashion that core RedHat packages are (i.e timely security fixes, backported if needs be, for the lifetime of the OS release).
From the ruby193 SCL page you linked to:
"Community Project: Maintained by upstream communities of developers. The software is cared for, but the developers make no commitments to update the repositories in a timely manner."
Yeah, if they are in CentOS land it will be a bit touch and go (as usual).
But if you have a redhat subscription they are fully supported. I should have pointed that out in my first comment though, thanks for bringing it up :)
"All Red Hat Software Collections components are fully supported under Red Hat Enterprise Linux subscription terms of service. Components are functionally complete and intended for production use. " [0]
From the ruby193 SCL page you linked to:
"Community Project: Maintained by upstream communities of developers. The software is cared for, but the developers make no commitments to update the repositories in a timely manner."