Might be worth speaking to Weber first. Here in the Uk and The US website they're releasing The Weber Care kit (certainly for the EX4) not sure about the EX6.
It looks like a direct replacement for the GBS system and sits on the right hand side of the smokefire and all the accessories fit into the frame kit. Not sure whether you need to buy new grates or they fit onto the right hand side of the current ones.
Details a bit sketchy at the moment, but Weber should be able to tell you exactly what you need and if it works with the EX6 as well.
Bring your kitchen outside, and create food never thought possible in your grill, with the WEBER CRAFTED Outdoor Kitchen Collection. Simply replace your right-side cooking grate with the WEBER CRAFTED Frame to unlock new grilling possibilities. • Fits SPIRIT 2016+ gas grills and SMOKEFIRE...
www.weber.com
Bring your kitchen outside, and create food never thought possible in your grill, with the WEBER CRAFTED Outdoor Kitchen Collection. Simply replace your existing cooking grates with the WEBER CRAFTED cooking grates and unlock the possibilities with custom fit grillware. WEBER CRAFTED frame kit...
www.weber.com
I think it's a better idea certainly for the EX4, I have the GBS system and I use it regularly on my EX4 with different accessories I own. But everything sits in the middle of the grill so you lose so much space either side and with this new system, you'll still have the left side to cook other things whilst using the accessories
Just noticed @jnordstrum thread on the EPX6 has some photos posted and the grill system certainly looks like it has the new Care Kit system supplied with it.