According to a person posting in the comments section on the kickstarter page under the username of a LineageOS developer, the Mediatek processors make it difficult, but not impossible, to produce ROMs. Mediatek does not release the source code for their firmware. There are claims on the web that Unihertz did not release the source code for their earlier phones either.
On the positive side, according to the company, the bootloader will be unlockable. That's from an official response in the kickstarter comments section.
Librem 5 shipping... https://arstechnica.com/gadgets/2019...nulinux-phone/
The comments are worth a look. A few mentions of webOS, pinephone & other devices on this thread. But though there's a pic pf the Pinephone including the LuneOS logo, no mention of that. :-(
I'm posting this for "interest", rather than as a serious LuneOS candidate. It seems to run an OSS version of Android (never heard of microG before), so there should be potential for Lineage / Halium if the bootloader is unlocked. But beyond that, I don't know if LuneOS could comfortably support the aspect ratio. Essential’s new smartphone has the aspect ratio of a TV remote