This double-shift, which we dubbed the "Westercon Two-Step," has been in the works now for some time, while our respective committees worked with our facilities and consulted with LASFS (owner of the Westercon service mark). Tonopah's facilities were very accommodating and had no problem with postponing Westercon 74 for one year. Westercon 73 was obliged to wait until Washington State governmental orders impacting large-group gatherings covered their planned dates. When that happened late last week, they met (online, of course) with their hotel, which agreed that the convention couldn't take place as originally scheduled. It took a few days to iron out the details and to put the finishing touches on the joint statement. It's a little tricky to make such things happen when there are two separate conventions (despite the conventions having the same name, they're independent of each other), and consequently there was some early leakage of the change.
As I responded to one person who asked, "Were you blindsided by this change?" the answer is "No, we have been planning on it for a while now." The message just was a little unevenly distributed, as people from Westercon 73 (whose members had a more urgent need to know anyway) started informing folks about the change.
I've changed the Westercon 74 logo in most places, but not all of them, so if you for some reason really want a piece of Westercon 74 merchandise with the 2021 dates, you still have a very short window of opportunity to go over to Zazzle.com and buy something before I get around to modifying the logo there for our shirts and other merchandise. (Of course, changing the logo here on DW/LJ means that every post before this one referring to the original dates will look odd in retrospect.)
I guess I have a new mouse pad and can-cooler I need to buy.