One thing I will definitely miss...the pins. Not important, and I didn't try to collect them all...some just didn't appeal to me. But I would be willing to bet quite a few companies already had the pins in hand...and the ones incorporating a 2020 motif are a loss for this year. With luck some might be available next year, unless the companies have them for sale on their websites...
I just received several of the GenCon 2020 pins and my t-shirt from offworld designs in the mail...but I will miss looking for the others.

I'm sure that most if not all companies who plan on being at Gencon
spend months prior generating extra product, special release products,
swag, advertising, etc..

Why not do everything shy of actually being
at Gencon at the ICC to still make it shopping
at Gencon?

Just my 2 shiny coppers.

For the virtual dealer hall, no matter what fancy tool Gencon buys for an online trade show/vendor hall, just make a list somewhere. Nothing fancy. Company Name, description and URL is enough. The map Gencon puts out every year of the vendor hall is user unfriendly for people who just want to go to the company website, not find them in the vendor hall.

Every year, Living Dice has published the list with links to websites for all the Gen Con vendors.  I don't know if they'll do so again this year for the virtual dealer hall.

The purchases I planned to make were in person only available items, from european companies to avoid shipping and items that are not offered online. An online vendor option may not help any of these items and would be vendor specific.