If you haven’t already get in touch with support@lulzbot.com about this and they should be able to help you in either ordering a replacement pin/getting you the necessary info for fixing the connector.
I cant tell which wire in the back that pin should be connected to but on mine ALL those pins have wires going to them so id say its definitely NOT just a guide pin. Im actually in the exact same boat as you though. I put my printer away in 2018 right after i got it due to health issues. I dug it out today and am having a few issues… Unfortunately my post about it got blocked by some spam filter!!!
Id definitely call Lulzbot for a repair harness, unless you can jump those two wires back together with a temporary connection. Just make SURE the wires cant touch anything else.