Settings still there after upgrade/erase flash?

Edit: seems to be just a coincidence as some settings were not preserved; probably had most of them as default.

Just upgraded my gateway to 1.6.0 via the web upload tool and though I used the erase flash option, It seems my settings were preserved (intervals, etc). Which is actually a good thing…
I had previously used “commands/MQTTtoBT/config={“save”:true}”
so is this normal behavior or just a coincidence?