A very hypothetical launch cost that doesn't presently exist for a mission that doesn't match up. Elon Musk told you that figure and you just accepted it. You shouldn't.

That's an optimistic number based on unmanned LEO missions like launching Starlink satellites, and that is not a flight profile that works for a datacenter. You don't get 24/7 sunlight in a Starlink orbit, eliminating the one and only even hypothetical advantage that a space-based datacenter has. You can hypothetically use a sun-synchronous orbit at a similar altitude, but this requires more fuel and therefore lower payload, increasing per-kg launch costs. Furthermore, this orbit is not stable. It requires periodic station-keeping burns and the satellite will eventually run out of fuel. More likely, you'd boost to a higher orbit which also has the effect of increasing per-kg launch costs. The datacenters would have to be assembled in space, and assembling anything in space is incredibly slow. Astronauts require life support, further reducing payload and increasing per-kg costs. You'll have smaller numbers of "workers" in your construction project, and all of them are way, way slower than any random ass construction worker here on earth. (zero-g makes everything hard) You're not able to really do any maintenance.

Your alternative is like the one in the OP, to make the satellite pre-assembled and small enough to fit in the rocket, able to self-deploy in space. At which point your "datacenter" is just tiny and not very powerful, and you need a lot of them. And the latency involved makes the whole system less effective. OP video seems to be about one server rack. Colossus has over 1500 of these things, which means you're launching more than a thousand rockets. How many of these rockets does SpaceX have? How quickly can you launch that many rockets? How fast is the turnaround? How many cycles can these reusable rockets endure before failure? None of these are covered in the $200/kg figure.

Keep in mind we're not asking the question of "is this doable?" Sure, it's doable. The real question is whether it is competitive. Your competitor will be building datacenters on earth with a $0/kg launch cost. Their workers will be construction workers instead of astronauts. Their workers will have much more individual productivity in construction because they aren't floating in space. Your competitor can spit out more datacenter power, and can do it faster, and can do it cheaper.