A sorcerer does not need to spend an hour per day to have their spell slots refreshed each day, it just happens after they rest.
However, my understanding of the arcanist's spellcasting is that they do not gain new spells per day until after they prepare spells, even if they didn't want to change their spell selection. Correct?
I assume this also applies to the vigilante-warlock (playtest-ultimate intrigue)?