I would not look at fares until 90 days out from the cruise and you will be rewarded with lower fares for a few different factors:
- May 2024 may have lower demand than right now. The post-Covid travel boom will be subsiding as people have taken those long-delayed trips.
- The economic conditions will likely be different. Some of Europe, e.g. Germany, is already in an official recession.
- Available capacity will likely be higher. LH is returning at least 4 A380s to transatlantic service by the end of this year, nearly doubling capacity vs. a typical A340 with each flight.

Check originations from a more competitive hub like JFK or BOS, or look for/be willing to take connections from ATL through those hubs. You'll save money.