They don't appear to be without severance[1].
>Today is your last working day at the company, however, you will remain employed by Twitter and will receive compensation and benefits through your separation date of February 2, 2023.
>Within a week, you will receive details of your severance offer, financial resources extending beyond your Non-Working Notice period.
[1] https://www.businessinsider.com/read-blunt-email-telling-twi...