I think he is just happy to play tennis again. He loves the sport and now finally he can play it again after a long recovery from serious injury. Just competing is probably feeling very good and everything else, like title, is bonus.
agree on this, I always remember Leyton Hewitt, that played Wimbledon for few season, after almost being retired, because he can get a wild card, based on previous performances
and it is probably a lot of fun for him, without pressure to win it, play a few rounds (which is great success for every player) on it, and be part of big tournament, you do not have to win every (and in these years and conditions, nobody expects a lot from Murray)