Here is a well-known Q/A about draw overlay permission issue. I observed same behavior on my previous apps also, i.e. it was automatically granted when the app is installed from Play Store.
In my recent app, however, I observed that that permission is not granted even if it is installed from Play Store. At first, I thought that this might be a specific problem for our test devices. However, I wanted to be sure about it by tracking the number of such lack-of-permission situations in the wild through my favorite analytics tool.
We published the version that notifies about this incident yesterday, and the analytics say that we had to manually request for this permission at 80 users, in just 1 day. Ouch!!!
The analytics say that this problem occurs in almost all Android versions, from 6.0 to 9. So it is not the case for just a few versions.
Is there any change about this permission recently? Or, does Play Store have some kind of a whitelist (e.g. Facebook takes it automatically) to grant this permission?
