I have a 2018 EX built and purchased in February 2018. It did not come with backup sensors so I had the dealer add them.
1. The control to turn the sensors on and off is in the back right panel near the lift gate. Very inconvenient.
2. The beeper is in that area too and very annoying to back seat passengers when it screeches as you shift to reverse.
3. They were useless at first due to sensors being installed upside down.
They do add a little safety over the backup camera, but I would not pay much for them. The dealer showed them as $0.01 option to meet my bottom line price. I was about to ask for a refund when they finally fixed the sensors. Every penny counts.
It is not a standard option on the EX-L but can be a dealer added option to appear it is factory. Pay close attention to the window sticker and you will see what options are added at the factory and what options are added by the dealer. Almost all dealers will post a picture of the window sticker in the online listing of the vehicle so you can see what options are actually installed.
According to Honda's build site, they are optional on LX through Touring models and standard on Elite models.