Summer 2020 is fast approaching! Everyone will have the ability to sign up for a Pre-release org on April 23rd. However, if you have a left-over Pre-release org you can get a sneak peek a bit early.
It appears Summer 2020 will bring after save flows (AKA Process Builders) directly into flow builder. You no longer need a process builder to launch another flow. It also comes with an improved UI. Here is what it looks like:
I plan to poke around some more and will post more findings!