You don't think "960MW nuclear data center campus" sounds like the power plant is part of the campus? I do.
A campus is a group of buildings and land that are part of one institution. I've been in multiple campuses that have power plants (and where the primary purpose of the campus is not generating power).
The idea of a datacenter campus that makes its own power is a reasonable one.
The title doesn't say "next to". It says "960MW nuclear data center campus".
What makes it "nuclear"? Well in this case it's because it's next to a nuclear power plant, but it would be just as valid to use that wording for a campus that contains a nuclear power plant. In fact I think the latter is more straightforward.
And funnily enough if you look at the picture, it looks like it's one big campus too!