If this is really an issue worth solving, doesn't it need to be solved for all cases, both traditional #foo links and also these new pattern-style links?
I can understand that this new mechanism will probably increase how often it can happen, but blocking the new mechanism would only solve part of the problem. To solve the whole problem, you'd have to do something like turn off lazy loading.
Anyway, if the reason the person is visiting the page is to read the section about cancer, aren't they usually going to manually scroll to the section about cancer a lot of the time? So the resource will still be loaded, just a little bit later. The scroll bar is moving to that position either way. The only information leaked is who moved it, the referer or the end user.