I wonder if (until we find a vaccine for COVID-19, or it naturally burns out) in the near future we'll see a shift back to more single camera shooting instead? 

Could mean more shooting days, but there could be a strong desire to shoot with the smallest minimal crews possible. As the bigger the crews, the bigger the risk someone comes down with COVID-19, causing the entire production to be shutdown!

With one exception, I can see the sound department needing to add an extra boom op than they'd usually budget for. Because lav-ing a person is quite intimate, I can see for the next few weeks/months that lavs will be avoided. Thus it becomes even more essential than usual to make sure you get the best possible coverage with the boom. 

Wonder too what will happen to the generous film incentives these scripted productions get from states/countries? When their state budgets are already under massive stresses from increased costs and a reduced tax intake, they'll be looking to cut "costs" (although I'd argue it is not a cost, but merely a tax rebate? Tax money the state would have never got otherwise, if the production wasn't shot there).

These tax rebates / film incentives will be especially vulnerable to attack if they were implemented under the basis of being "marketing for the region" to help promote tourism. Was where is the tourism now?? Dead. There is very little tourism to promote, and many regions would not want to promote tourists coming! As they want to lock out everyone who is "non-essential".

Moving on from the scripted narrative world, to the corporate world of videography and also event shooting. Am expecting a rise in live streaming. Soon nearly everyone will need to offer, just like the shift from SD to HD, everyone had to offer HD. (and we're almost at that point with 4K now)

Who charges extra for 4K these days? Most don't, or only a small token extra amount. 

So will be the case with live streaming I think, you'll either throw it in to get the job or just a modest upsell extra cost. 

And because an ATEM Mini Pro costs only US$599 you can easily eat that cost, as if it only gets you a couple of extra jobs that you wouldn't have otherwise, then it is worth it!