Yes, most likely! That is a common approach for 'soft bounces' in most list management systems (e.g. MailChimp).
The problem here is Gmail has been throwing out "NoSuchUser" errors which are an instant unsub in most systems because Gmail takes repeated delivery to non-existing addresses into account for deliverability purposes.
I'm extremely paranoid about email hygiene, tiny bounce rates and high delivery rates, so we aggressively unsubscribe troublesome addresses (often to the point of getting reader complaints about it) for many reasons beyond that, however.
The problem here is Gmail has been throwing out "NoSuchUser" errors which are an instant unsub in most systems because Gmail takes repeated delivery to non-existing addresses into account for deliverability purposes.
I'm extremely paranoid about email hygiene, tiny bounce rates and high delivery rates, so we aggressively unsubscribe troublesome addresses (often to the point of getting reader complaints about it) for many reasons beyond that, however.