My takeaway from that article is they don't, and haven't.
The splash screen for installing a package not from the play store is there to protect the end user. Without it there would probably be a much worse unwanted software issue on android.
I've been "side loading" or just "installing" applications on my android devices since the nexus one, without the help of the play store.
Discord is trash, had issues with a KBDFans product, something as simple as a search of a forum would have given me the solution. I had to talk to a human to get the required information. They sent me a link to a firmware to download and all was good.
If I was able to search a forum it would have been a 2 minute job, but I wasted someone else's time, on the other side of the globe.