My personal $0.02 on convention cancellations due to the pandemic:
Even if we're exceedingly lucky and this thing eventually burns itself out like the 1918 flu pandemic did, it took that particular disaster roughly two years to be over and done with. Even if it only takes a single year from now because of a variety of factors (including the fact that we have better medical and scientific knowledge and treatment techniques than in 1918-19), that still means that it might not be safe to hold conventions until May 2021. That means that cons running from Anime Central this year until Acen next year won't be able to be held - or held in the same way they used to be.
This also means that local events ranging from Acen through Gen Con, Wizard World, Windycon, Capricon next year and possibly Acen in 2021 might all be washouts. No one can entirely predict how the pandemic will play out by then, but if the Illinois rule holding public events down to 50 people or less continues to be necessary that would completely wipe out all of the aforementioned conventions that are held in Illinois. As for Indiana, their events have to follow state law as well. And large events held outside the area like San Diego Comicon, Dragon*Con and Worldcon would have to follow their respective local law - or just admit that the accompanying liability issues just aren't worth the risk. And, IMO, they're not.
With all of those factors laid out on the table, this much can be said - conventions may have to sit on their budgets until a time they can be held safely. Vendors may have to rely on online or mail-order sales instead. And fans may have to find new ways to network or hold online "conventions" until we get out of this mess. Yes, the situation is bad. Quite bad, as someone who both staffs and attends conventions. But it's still far better than the alternative.
