Here is exactly what happened for a recent application from Vancouver BC in 2018.
12. Sept. - Submitted online application and paid both Visa Fee and IHS Surcharge
14. Sept. - Attended Biometrics Appointment at the VFS Office on Hastings
20. Sept. - E-Mail from Sheffield saying the application is being prepared for consideration
5. Oct. - Documents Received via UPS delivered to my home at 12:00PM its been approved
Absolutely no further communications between 20.Sept and 5.October. I only found out I was getting it back that day by entering the UPS tracking number on the UPS Site which said it was out for delivery.
The Visa on the passport says its been issued on 27.Sept. and then it was sent back to the VFS Office in Vancouver who then mailed it out on the evening of the 4th of October for next day delivery service.
You get all your original documents back including your original application, document checklist, bank statement, passport with the vignette/visa inside, and a letter saying that your application has been successful and to bring the letter with you to the UK when you go with an address of when and where to pickup your BRP within 10 days of arrival/before expiry of your vignette.
I know a mate that works at a company that deals with many working holiday applications to the UK and they say generally 15 business days after the biometrics appointment which was exactly what happened in my case. I was actually panicking when I found out they were sending back the documents and did not receive any emails regarding a decision thinking it was rejected, but it was not!
Hope this helps.