How do I keep previous versions of an Adobe CC application as I install the new one?
What is the trick? On install, uncheck "Remove old versions". That's it! And you'll keep your older versions of InDesign (or Photoshop, or whatever).
You can also enable auto-update and tell it to keep your old versions.
How do I get back a previous version of an Adobe CC application that was unintentionally removed?
This option is a little less hidden than it has been in the past. It really is quite simple: