https://community.netgear.com/t5/Idea-Exchange-For-Home/idb-p/idea-exchange-for-home

Enable MR60 router to be added to an existing Nighthawk Mesh WiFi 6 network (MR60).  It's cheaper to purchase systems than individual extenders/satellites.  

In my case, I had an older MR60 Mesh Network that came with 2 satellites.  1 of the satellites stopped working.  Instead of purchasing one new satellite, I chose to purchase the same package because it was on sale.  

Providing this fuctionality would enable customers like myself to make the MR60 router act as a statellite without being wired to an existing satellite or the base router.  Working as an "wireless access point" would not provide any benefit because it would be a "new" network with relative the same coverage as what the device is wired into.