Back on April 28, DC's comic book titles began going on sale on Tuesdays - both digitally and in print (with participating comic book shops). Comic books from other publishers remain scheduled for a Wednesday on-sale date.
DC has explained their reasoning for the switch to Tuesdays previously, and multiple sources has confirmed that when Diamond resumes distribution, their customers - the comic book stores which order from them - will be allowed to put DC titles on-sale Tuesday, ahead of the Wednesday releases from all the other publishers. It's up to the retailers if they will sell DC's on Tuesdays or hold them to go on-sale concurrent with the non-DC titles.
So what does this mean for those who rush out to buy comics each Wednesday?
Well, those comics will still be there Wednesday if the place you buy comics from is up-and-operational. But if you want to read DC comic books first or have concerns about sell-outs or spoilers, they will be available Tuesdays in print and digitally. You'll just need to make a trip back to wherever you by comics from on Wednesday (or after) to pick up any new non-DC titles.
Marvel and other Direct Market-focused publishers have not stated if they plan to switch to a Tuesday release schedule, however their recently revised June 2020 solicitations adhere to their traditional Wednesday on-sale dates.