There’s just not enough information to calculate estimated revenues. The author just assumes 10% of all DAU are paying customers. Each Zoom session only needs one host. The host will have either a free account or paid account. Even if each zoom session has one paying host and one attended, that’s 190 million New DAU, (200-10). Best case scenario 95 million new hosts. That’s assuming each Daily user is talking to a paying host. And each zoom session only has two people. Highly unlikely.
And suddenly if people go from 1 zoom session a week to 5 due to coronavirus, that just increased DAU 5 fold without really adding any overall accounts/users. Existing paying customers are just using it more. That’s why Monthly Average Users is probably more reliable to calculate revenue growth, but I cannot find a statement from Zoom with that information.
I don’t see any meaningful way to calculate revenue growth. Even being off new paying users by a few percentage points can have a big difference in terms of revenue. And we don’t even know what the next few months have in store.