Please move this discussion to Products as it is Marketo-specific, not a general marketing topic.
Has this lead been paused or removed from the engagement program triggered by the change in email address or company name? If not, then they will remain in the nurture stream and they will receive content to the new email address. If they have been paused in the nurture, just change their cadence to normal. If they were removed from the engagement program altogether, then you can add them back to the stream they were last in my observing their activity log. Once back in that stream, they will not receive the same content they received before, so they will go back in the stream position as they were before.