just to mention, to me as someone who has toured for a long time, fully loaded means fully loaded, and these bikes certainly arent marketed as this, but specifically as for want of a better term, the "bikepacking" setup--which generally means less stuff and certainly less stuff up front, weight wise.
it certainly makes sense, as you said, equipment is generally lighter nowadays, tents and whatnot, so it certainly is a lot easier to have more comfort with a lot less stuff than lets say 30 years ago when I started.
I reckon just about any bike can easily handle the more or less amount you mention, and given these bikes are made with the intention of going on rough roads, they'll be fine.
For me fully-loaded means carrying gear on front and rear and gear should include sleeping, cooking, tent, plus room for a reasonable amount of clothing and personal items. I would not recommend this kind of carbon-rig for expedition touring such as I did on my Alaska tour.
BTW: I'm not near ready to trade in my over-built steel touring rig yet. But maybe someday as if I hear-and-see positive results IRL.