Jun 19 21:28 2016, Joe Delahaye wrote to Markus Reschke:
JD> Apparently the WRT series of routers from Lynksys, will retain the JD> ability to use different firmware, such as Open WRT. They are the JD> only company doing so, and it is the only modem that will allow that.
Presumably it's more likely just marketing since tons of other routers are also supported by OpenWrt.