I believe your sources are referring to the $5 YVR AddFare, which is charged when your eastbound journey originates at YVR, Sea Island Centre or Templeton stations and terminates at any other station.
This $5 charge applies if you use stored value to pay for your journey starting at any Sea Island station, or if you buy a DayPass on Sea Island, and exit the system at a station not on Sea Island.
The TransLink web site explains the applicability of this charge in detail:
The $5 YVR AddFare is applicable on the following adult and concession
fares for eastbound travel:
- Single-use tickets purchased from CVMs at the three Sea Island stations.
- DayPasses purchased from CVMs at the three Sea Island stations.
- Compass Card Stored Value trips that originate on one of the three Island Stations for travel beyond Sea Island.
- Contactless American Express, Mastercard or Visa credit card or mobile wallet Tap to Pay fares.
The following fare media is exempt from the YVR AddFare:
- Monthly Pass holders.
- Program pass holders.
- Burkeville resident program cards.
- Customers using DayPasses not purchased on Sea Island.
- Customers using single-use Compass Tickets not purchased on Sea Island.
- Customers travelling between Sea Island stations.
It used to be that you could buy the DayPass at the airport 7-11 to avoid the AddFare, but they appear to have closed that loophole a few years ago. If you arrived in Vancouver some other way, then buying the card and DayPass anywhere off Sea Island would work. If you will be in Vancouver for more than a couple of weeks, then buying a monthly pass is an option which will let you avoid the charge.