So, it’s done. Official armv7 and armv8 support 
Please grab your official betas from Media Server Downloads | Plex Media Server for Windows, Mac, Linux, FreeBSD and More as Plex Pass holder. Just remove the old installer (no data loss!) beforehand.
For example: sudo apt remove plexmediaserver-installer && sudo dpkg -i plexmediaserver_1.15.0.659-9311f93fd_armhf.deb
