sometime between tomorrow morning and Saturday
I would think tickets are so scarce as to be moot but it seems like the vagueness means there will be multiple opportunities. i.e. the first round of people will get a shot, and if there is anything left after that (because not everyone used their code or bought the maximum allowed tickets) there might be a second or even third draw.
Happy to report (but sorry to brag) that buying 2023 partials did in fact get me into the WS presale, having done it too late for the NLCS.