Thanks to Kozmic for pointing out the Legends of Runeterra weekly reset for the Vault changed to Tuesday instead of Friday. This turns out to be important for players because early access starts on a Thursday.
On Discord one of the LoR developers, Strokke (who I believe is Blake Midstokke, Gameplay Director), confirmed this change.
Hey all! I have an answer on the "store resets" question.
Store resets will happen at the same time as vault openings, which will be tuesday. The Jan 23rd and Jan 24th dates will both fall outside of that window, so pre-registrations will only get the advantage of one day earlier (not one day earlier + a bonus reset of the store)