The letter is material and required an 8-k to be lodged by Coinbase.
You should NOTE this. That Coinbase is technically in default from withholding the SEC mandated 8-k form
It comes with possible felony charges. And, the CEO could be banned from operating an exchange or even a public company by not telling the market of this material event.
Funny how much h of this stuff I know.
Look up Rule 144, SEC.
Turn out, they (main pre-Ipo holders and officers) are legally bared and in criminal breach if they sell a single share or even take I lien on then for failing to disclose.