Subscribers who are still in the sequence will get them if you add them to the end of the sequence.
For any subscribers who have already received the last email, then it depends. If they are added to the sequence by a rule, then they'll get them as well. If they are added by a visual automation, then they will be marked as "completed" when they get the last email in the sequence, and won't get the new ones. But there is a new setting in sequences that will allow you to hold subscribers in the sequence to get new emails. There is more on that here: https://help.convertkit.com/en/articles/5192801-how-to-hold-subscribers-in-evergreen-sequences109
Hope that helps!