Yes, the XR800 was the CX model at the time. The XS800 had Headshok front suspension but was otherwise the same. Wheels are Campagnolo Khamsin. There was a CX version of the next level up Scirocco wheels but I don't know how it differed from the road version. I assume the rim was slightly wider. I have the same tires on another gravel bike that has wider WTB rims. I don't really notice the difference but I assume the tire profile is wider/flatter on the wider rims.
The move to discs was gradual. For at least 10 years they made both disc and rim brake versions. 2003 was the first year for the Cyclocross Disc frame, the bike was called XR1000. There were both rim and disc versions of the aluminum CAADX and the carbon SuperX as late as 2013. By 2015 they were all disc. I don't have a 2014 catalog handy to check.