This has been discussed in a closed discussion starting on july 24 "Ubuntu 14.04 LTS server syncthing problem installation and autostart"
So I’ll be short here. I installed from tar.gz on an Ubuntu 16.04 and from .deb on a Lubuntu 16.04, and I had to add the autostart. Also these autostart open https://localhost:8384/ , which doesn’t seem requested for Syncthing to work. It would be great if the autostart were autoinstalling, and if the start of the software didn’t trigger the internet navigator.