Honestly - I suggest you hold off until you either interact with him more at work or he moves on from his current role.
I find it inappropriate to add him on Facebook or to follow him on Instagram. I have some male work "friends" and we had a chat about this once (some girl in the team tried to add them on FB) and they thought it was inappropriate (which I agree with). You can't just send a FB request to someone you've only seen once via Zoom. He might be single, but what makes you think he's into women or he's even looking to begin with?
I'm not sure what "re-assigned" means in this case, but I would take it slow because you don't want to come across a certain way in the workplace.
About two years ago, I met this absolutely stunning guy at work. Exactly my type. Simply gorgeous. I'd never met anyone like him before (close, yes, but not the exact embodiment of what I liked). I never noticed him until I one day (two months later) realized he kept glancing at my desk every single time he walked past. In addition to that, he would literally show up everywhere I went (in a company of more than 2k) employees. I'd be chatting with a colleague in the kitchen or somewhere in the hallway and he'd be walking past out of nowhere (he could see every coming and coming from his desk though). It was so eerie that I almost was scared he'd think I was stalking him, when it was literally a coincidence each time, really.
Anyway, fast forward, two years later, I'm still thinking about him (the lockdown didn't help either) and wish I had made a move, but again, I didn't want to come across as inappropriate. I didn't know his background and steered clear. I found his Instagram a little while later and he had moved on to another project at that point (thus worked in a different side of town), but never dared to do anything. He's since deleted it and I'm still crushing on a ghost! Moral of the story - you don't want to end up like me wondering what if this and what if that two years later, but be cautious when it comes to approaching co-workers on social media. Perhaps add him on LinkedIn first? Keep it professional for now and perhaps once he moves on, you can try to get to know him by asking for advice about a specific topic (since he's a superior) etc.. and perhaps take it from there. Just a thought.
