Flashing from Stock to /e/ results in failure to boot (boots into fastboot and that’s it). Almost all users will end up there and then research “what the hell went wrong”. Needs an urgent update to Pie.
LineageOS for MicroG seems to be Pie already for polaris (since 16.0) so it should be relatively straight forward for /e/ to catch up: https://download.lineage.microg.org/polaris/
When the official migration to /e/ OS 9-pie is completed, there will probably be no OTA. Already LineageOS 15.1 couldn’t be upgraded to LineageOS 16.0 via OTA, but had to be installed manually. This is very easy with TeamWin - TWRP.
It’s solely up to the /e/ team manager to decide which device is migrated to which release and when. The aim is to migrate all devices supported by /e/ to a higher firmware level in the course of the upgrade. When this change will be completed - I have no idea.
Yes, I’m aware of that list. It includes even more devices, e.g. S7/S7 Edge (Oreo) and so on.
However, as a measure of how long it takes to rebuild a new build [UNOFFICIAL BUILD], I remember the activities of@Unknown. He alone built several dozen [UNOFFICIAL BUILD] in October 2019 - albeit untested, but quite successfully. That was an enormous and previously unparalleled achievement on his part, which I can now put into perspective.
I can live well with the fact that my favorite devices will not receive an /e/ OS upgrade for several months or not at all. There are always alternatives, even if only with compromises. /e/volution is unique so far.