They are already a public company.

93% owned by the founder.

Hamuko an hour ago | parent | prev [-]

You can take a public company private and then run it to the ground. See also: Twitter.

How does that work now they are a subsidiary of SpaceX?

Does that make the rotting corpse of Twitter public again?

Yes. Although the amount of SpaceX stock that's available for public is fairly little.

	▲	victorbjorklund 14 minutes ago \| parent [-]
		And those classes available for the public has less voting rights than Elons stock so even worse.