Of course, at this stage, we're taking a once bitten twice shy stance, but let's lay out the facts here. You can see in the header image that this information is coming from a site called TMview. This is a trademark search site for the EU, and is linked on the official Office for Trademarks and Designs website as a trademark search tool. It is definitely a legitimate site.
So we now have to ask if the trademark has been legitimately applied for and registered. It is registered under a legal firm called F.R. Kelly, acting on Blizzard's behalf. You can see an image of the section of the record here, or search it yourself. The law firm are specialist patent and trademark attorneys. Also notable is that the trademark status is currently under examination, with the application received two days ago. About when MMOC first published their story. What's more, the law firm is the same one that registered Reaper of Souls.
You can see that what I'm trying to do here is not assert, but simply present what we can gather for your consideration. Was it a cover-up? Are Blizzard just grabbing the trademark for safe-keeping? We don't know. But it's certainly interesting. Caution is advised.