This article reads as if nobody wanted to legalize it which is wrong. The population was asking for legalization for many years now. Finally the new "traffic light coalition" made the change.
The short awnser is: https://wiki.lineageos.org/devices/
The m8 also wasn't supported anymore but since mine will mostly/only be used for media playback (you know, great speakers) so security isn't my bigest concern.
Well basicly all instruction you need and it's explained pretty well on the lineage os website itself.
https://wiki.lineageos.org/devices/m8/
The hardest part was getting the unlocktoken since htc doesn't take new htcdev registrations. I got hellped by a member on Lemmy who had a old htc dev account.
A member of lemmy wrote me that he had a htcdev account from years ago and offered me to send me the unlock token for my phone after sending him the OEM identifier token.
Wild theory: could it have been malicious compliance? Maybe the dev got a written notice to do it that way from some incompetent manager.