By my count there are ten species for the 2024 Players Handbook so far:
Human, Elf,
Tiefling, Dwarf, Dragonborn,
Halfling, Orc, Gnome, Goliath
Ardling
(Conspicuously missing from this list are: Genasi, Aasimar, and Aarakocra)
(Not impossibly, Ardling is for the Planescape setting instead of 2024.)
The number, "144 options for your characters background", can be 9x16 or 12x12.
(I suspect there organization of the background will be symmetric, under the influence of "12 classes" with "4 subclasses" each.)
If 9x16, it might be for nine species (sans Ardling), with 16 backgrounds each.
But 16 backgrounds per species seems like alot.
In any case, the many Backgrounds probably organize by "culture". Since some of these cultures are multi-species, I doubt there is a one-to-one correlation between species and backgrounds.
There might be things like "Aevendrow" cultural backgrounds. But there might also be things like "Waterdeep" cultural backgrounds.
Probably, there are 9, 12, or 16 prominent cultures of various kinds.
Then a symmetric 16, 12, or 9 backgrounds per culture.
It seems easier to expect 16 prominent cultures, with 9 backgrounds each.