Hard to separate the memorability of the abstract from the underlying material.

IMO the most memorable papers contain some unexpected simplification: a complicated problem turns out to reduce to something much simpler [0], perhaps for a counterintuitive reason [1].

So a memorable abstract should advertise that the paper contains some cute little trick. This may not help you actually publish though

[0]: Attack the RLHF problem with a simple classification loss: https://arxiv.org/abs/2305.18290

[1]: Frustratingly Easy Meta-Embeddings: https://arxiv.org/abs/1804.05262