Homo significans, “human who makes meaning”, is already a well established expression. So is homo interpres, “interpreting human”, human who makes sense of things.
You’re doing something more subtle: “seeking meaning in the universe, anticipating that there will be meaning”. It’s very close to homo interpres. But if you want to be more explicit: homo signa quaerens, or homo significationem quaerens.
No single word for “meaning-seeking”. You asked for Latin, not Greek.