Is he wrong?

He could be attempting to create a problem so he can take advantage of it.

Entirely possible he shorted SVB.

If the company goes into liquidation before the short seller closes their position, what happens?

You win but you may get stuck paying the borrow costs still for a while until either the stock is tradable or whatever happens with the resolution of the bankruptcy settles out (the residual shares potentially have _some_ value). In practice, before that, your broker or whomever you borrowed the shares from will probably just declare it a loss and close it out. They'll then get a little something from the bankruptcy, maybe.

That's assuming a traditional short, and not something like selling naked calls. In the latter case they just expire worthless.

Will only drive the stock price down so that another bank will buy them up. :Not sure if that's what he's aiming for.

Probably selling short

they aren't publicly traded

Wrong, they are, ... um were, publicly traded under the symbol SIVB. [0]

Trading Halted. They were down 66% on the day before halt

On 08-March-2023, they were trading at $267.90, by the end of the 9th, 106.08. By trading halt today, $39.49. Now, it's worthless. Imagine thinking you got a bargain at $106, or $39...

[0] https://finance.yahoo.com/quote/SIVB

Yup, it was Theil who started the bank run [0].

[0] https://www.fastcompany.com/90864395/silicon-valley-bank-an-...