It’s moot now that we know the true nature of LGM-1, but a too-regular artificial source could still be a beacon of sorts. A highly-regular signal like that could be a useful navigation aide: You can distinguish it from other similar beacons by its frequency (this is done with lighthouses here on Earth), and you can precisely determine your radial speed relative to it via the Doppler effect.
I was thinking that when I was typing it up; that’s why I put in the weasel words, “was dropped in part.” When I looked up the Wiki article I noticed the sentence, “Bell soon ruled out extraterrestrial life as a source after discovering a similar signal from another part of the sky.”
I would assume Bell concluded that this new piece of equipment happening to discover two widely separated civilizations using a powerful beacon was highly unlikely.
It’s kind of like when Linda Morabito found the first image of Io showing an erupting volcano, her first thought was, “Cool! I’ve found a new moon!”
