Canon's a term only relevant to Mongoose authors. The original canon on Hop drives is that they don't get deployed to a significant degree for another 8 centuries, but that "fact" is pretty much irrelevant to any actual game at the table. And may not be true any more. Absolutely someone is working on better jump drives, whether that's J7 or H1 or warp engines.
The issue of canonicity of the epic campaigns is mostly that they are obviously not designed to exist together. But if Mongoose wants to fix that or declare some canon and others not, they can. That declaration would still only be relevant to authors publishing official material.