Intel uses the "W" designation for its enterprise-class chips that typically live on the the HEDT platform, such as the LGA2066 CPU socket. It's weird to see a Xeon W chip on a mainstream platform, which in this case is the latest LGA1200 socket.
Could this mean that Intel is killing off the LGA2066 socket with no replacement? I guess that would also mean Xeon W is subsuming their E-series?
...or, maybe something else is going on. After they released LGA3647-socket Cascade Lake Xeons, branded as the W-3000 series, I can see a new pattern emerging. If W-2000 meant LGA2066 and W-3000 was LGA3647, then next-gen W-1200 could be their new branding of Xeons in the desktop platform, rather than Xeon E.
IIRC, Xeon E was the last Xeon line they rebranded, so maybe they felt that E didn't have a lot of intertia in the market, and W had more cachet. As odd as it sounds, remember: this is the company who brought Bronze/Silver/Gold/Platinum branding to
server CPUs! So, I could believe that someone in their marketing department might think "E" summons notions of "Economy", which sounds low-end, and wanted to move away from it.