Timed toasts are bad for accessibility too, see WCAG 2.2: https://www.w3.org/TR/WCAG22/#enough-time

Basically, the user should be able to configure toast messages; they should not autohide, or the time they hide should be adjustable, or they should be extendable within 20 seconds. TL;DR, self-hiding messages, dialogs, etc are not good for a11y.

That said, the toasts have a button where the user can undo the action taken, which is good for accessibility under criteria 2.5.2 and/or 3.3.4 / 3.3.6