IDK but is in the form of a haiku.

I think the mermaid one is pointing at the kids. The mermaid pendant is required for marriage so the fruit of that marriage is kids.

The general consensus on Reddit is

2 paths: either the new romanceable Sims, the Joja/community center or, our kids will be able to grow up

3 becomes 4: 3 current kids, 3 current main locations (valley, desert, island), 3 major galaxy weapons

Mermaids Fruit: Children will be able to leave the house, something with the Pearls, some kind of new fruit or fish

The mermaid gets her tits out, confirmed

Two paths is probably the new marriage candidates.

3 becomes 4, maybe something happens at the start of year 4 like at the start of year 3 with grandpa's statue?

Could mermaid fruit refer to pearls somehow?