I would expect the Model 978 to offer a straightforward option for analog bypass at stereo inputs. After all, every unit they've developed from scratch except the original Model 1050 has offered this, and only the Model 990 (based on someone else's platform) had the sorts of quirks you mention.

As for bass management, I kind of doubt we'll see something analog just for a single stereo input. For one thing, it is adding extra cost and complexity to a feature that many owners will never use. For another, they already have (or will have) a product that can provide such functionality for folks who really want to keep everything in the analog domain: the upcoming ICBM-2. I would expect the ability to convert that input to digital, apply bass management and other processing as desired, and convert back to analog - it's not as pure a path, but depending on how good the DACs are (and we've been told to expect very good quality parts there) it could be a very transparent way to achieve bass management.