I’m looking to update our studio to 2019.2.12 and I can no longer find the standalone installers anymore. The ONLY option I see is for the Hub.
I was assured a while back that we would not be forced to use the Hub and that stand alone installers would always be made available. So where did they get hidden?
They are still available but you’ll have to use the Hub anyway since, when you’ll open a project, it will require the Hub.
Download Archive, choose your version and click on the Download button on the right of the green Unity Hub button.
Yay for having to click on “Previous Versions” in order to download the CURRENT version 
As for needing the hub, unless something just changed, we haven’t needed it so far up to 2019.2.2
How were you instructed to install previously? And assured by whom?
I’ll have to find the post but I had asked about it early on when Hub started showing up because none of our artists have a connection to the internet and thus can’t install editor versions via the hub. We typically download the stand a lone installer and then use that for artist installation.
Here is the previous thread about Hub Offline, though in re-reading it now I guess it isn’t as explicit as I remember it being:
Bottom line though is we work in a studio where artists do not have a connection to the internet, therefore installs can not be made through hub. We CAN install Hub for them if it becomes necessary for working with the Editor at all, but it will not be able to connect. All our licensing is done through offline licenses. So far however the Hub hasn’t been required when using the offline installer, so we haven’t bothered installing it as it would be one more thing ot try and keep up with updating and what not.