The most logical conclusion is that this probably wasn't about money. Plenty of better ways to make money than telling people to give you BTC. I'm expecting a huge data drop on wikileaks/pastebin/wherever of private DMs, images, who knows what else.
People seem to assume everyone takes tweets at face value and won't do a double take when it doesn't sound like something they would normally say.
Even here there was plenty of people on HN who were claiming outlandish possibilities while it was happening.
Poorly executed, frankly. The tweet just wreaked of spam.
e.g., Vietnam is a livable place and GDP per capita is ~$2600. That'd get you a very modest living. GDP/capita is also up 2x from 10 years ago and 10x from 20 years ago. You could maybe squeak out 20 years with very modest living and few unplanned expenses and assuming the economy and thus cost of living doesn't grow tremendously (like it likely will).
Somalia would give you a little more value for your money. But I think if someone suddenly had that much money in Somalia, they'd probably be getting out of Somalia or hoping nobody found out.
Almost anything else I can think of would require either (a) substansal amount of starting cash (for example trying to crash Tesla's stock price), or (b) be almost impossible to pull off without getting caught (blackmail, or again stock manipulation if you do it in a big enough way to make some decent money).
In terms of risk/reward, assuming someone found some easy trick and wanted to cash out ASAP, this feels like the best option.
Alternatively, is it possible they bought options on twitter itself? It’s down 4% in after-hours (which is less than I expected, but still enough delta to make some cash).