I think the only real hope for pony conventions happening in the near future - by which I mean the next 3 months - might be axing the Mane Hall, doing everything in panel rooms capped to 50-100, and *winces* making half the vendors draw straws to see who survives the Thanos Snap
The last few survivors will be overtaken by new and hideous diseases
And the space platforms will be destroyed by attrition
The petering out of supplies
The natural effect of general decay
And there will be the most beautiful silence never heard