It's a confusing time for anyone who's trying to plan life beyond, like, a week from now. This pandemic has the status of everything up in the air, as no one truly knows how long COVID-19 restrictions will be in place. Will it be safe to go to an airport in August? Can I go to a concert in September? No one knows.
That's why Blizzard's official statement about BlizzCon 2020 is basically this: Your guess is as good as ours. BlizzCon is traditionally held in early November, and that's too far away to know if the show can be safely staged. Blizzard says "While we're all hopeful things will look better later in the year, the bottom line is that at this point it's too early to know whether BlizzCon 2020 will be feasible."
Blizzard also acknowledges that it might be several months before it knows whether it's forced to cancel BlizzCon or not. Most people generally try to book their travel and accommodations as soon as possible, but they'll have to grapple with the same uncertainty that everyone else faces right now. There are some global extenuating circumstances that need to be cleared up first.
A Note about BlizzCon [Blizzard]