I'd say it is a very strong reason to believe so. But on the other hand, alone the fact that the vendor issued a firmware update in the timeframe the certificate updates have been running is a very strong argument that the update process is safe (does not lead to hangs or incompatibility issues).

OTOH, it is not a guarantee that it is successful (does not fail with a defined error code). There are cases (lost/replaced platform key) that cannot be remediated just by installing a firmware update, but only by following additional steps (e.g. suspending Bitlocker and resetting setup defaults). But I would expect the firmware vendor to clearly communicate those if they apply.