The court ruled (my plain reading of the outcome) that a political party can select any candidate, in any way it wants, regardless of statewide primaries.
You'll remember some state primaries were ruled in Hillary's favor by way of coin flips...which Hillary won every time, a statistical magic trick.
So, IMHO, A24 doesn't mean squat other than the fact that a poll tax is not allowed. The courts say primaries don't matter since the party can rule by fiat and select any candidate it anoints.
I know you'll correct me if I have the facts wrong.
No, this is exactly the case.
And, State Primaries are held with taxpayer money so that political parties don’t have to spend money on the trappings of a vote.
There was a time (ended circa 1976?) that the parties re-imbursed the States for the Primary costs but, that got too expensive.