IP addresses of relays are still known in the network, and IP reputation firms may flag your IP as potentially suspicious. This may or may not cause issues when dealing with orgs that filter based on "known bad IP address" lists. I've had it happen before, where everything was fine until a few days after running a tor relay (not an exit node, just a relay) everything suddenly wanted more verifications I was not a bot, some paid video services started blocking me, and a few other issues. Stopped running the node and later things cleared up.