If you unblock a contact in WhatsApp, will they receive your previous messages - briefly?
No, if you unblock a contact in WhatsApp, they will not receive your previous messages. Once blocked, those messages are no longer sent to the recipient and remain undelivered.
If you unblock a contact in WhatsApp, will they receive your previous messages - in detail?
When you block a contact on WhatsApp, the blocked user is unable to see updates to your profile photo, about info, or status updates. Additionally, any messages sent from you while they were blocked will not be delivered once the block is lifted. This is because WhatsApp does not store undelivered messages for an indefinite period; instead, it attempts delivery up to 30 days after the message was sent. If the message cannot be delivered within this time frame, it expires and is no longer available for delivery.
However, if you unblock a contact on WhatsApp, they will be able to see your profile photo, about info, status updates, and any messages sent by them after the block was lifted. It's important to note that this only applies to future messages; previously undelivered messages will not be resent or made visible to the unblocked contact.
To summarize, if you unblock a contact in WhatsApp, they will not receive your previous messages sent while they were blocked. This is due to WhatsApp's policy of attempting message delivery for only 30 days before expiring undeliverable messages.