Conversely if there are no easily accessible apps by the 30th, then many will cave and use the default app, and turn what would be a tsunami of new users into the #fediverse a trickle -
I think the two things that need to happen is that there needs to be good native apps and the moderators need to move as well.
That's simply not true, the difference between here and there is the sheer volume that produces the quality.
You also need that volume of users to get the breaking stories posted, curated and commented on - where there's a story and an expert commenting within minutes. And memes, of course :D