I feel like I missed something, but see a bunch of people sharing this in chat, twitter replies, etc. I can guess based on context that it's like "no equal", or something? Doesn't help that it's also nigh impossible to search for a meaning as most search is going to strip out the special characters. Thank you for anyone that can help the old guy.
Also I too may have shed a few tears during the goodbye stream so I've just wanted to figure out what other folks were meaning with "<>".