As ever with these kind of eccentricities, if the candidate is good enough they can pull it off, but otherwise it's a orange flag.
Sorry, if someone is hiring based on whether I have a cricle-jerk social media account, then I don't want to work there.
I genuinely don't understand why you would think it's odd?
But reading that signal partially will filter out improperly. Aside from privacy, candidates who value their time don't want to be disturbed unless they have initiated.
Someone whose LI profile doesn't exist (or has just 'go to my site') is more experienced at the game.
Good god! Where in the world are you?
Here in Blightty, it wasn't that long ago having a linkedin account would count against some of our candidates.... as a candidate must have had their head in the sand not to be aware of the toxic behaviour of linkedin (spamming personal contacts) [1].
[1] https://www.theguardian.com/technology/2015/oct/07/linkedin-...