If I block someone and try to text them and then unblock them later will they still receive those messages?

I asked ai out of curiosity, it mentioned Apple having an iMessage delivery queue (not sure if that’s true or how it works) so it stated even after you block someone then send a message they can still receive it after unblocking them within a certain time frame I believe it said they hold the messages in the queue for 24-48 hrs. But not sure of the exact amount of time.