This came up yesterday with some visiting cyclists. What would be useful would be to filter hosts who can help or give advice with mechanical issues. Sometimes a touring cyclist needs guidance as to what shop would be able to help them out, given their situation. And those to avoid.
They had a problem with clicking in their rear rim (joint) and decided to get it replaced, rather than run the risk of it self destructing. It was a 40 spoke (tandem) and they could not get it sourced in Kingston ON. After a bunch of scurrying around they found one in Ottawa. Rented a car and drove up, only to find out that promises to rebuilt the wheel were empty (store not to be named but I'm not surprised. I wouldn't have sent them there, had I known). They ended up buying a truing stand at MEC. and rebuilt it themselves. In hindsight they could have contacted me but that didn't occur to them at the time.
I worked as a bike mechanic for nearly a decade, and know plenty of good options (as well as those to stay away from). While I'd be confident in my own knowledge when I tour, I recognize many do not have my experience, and would need an informed local to help them out.
Recently I helped a visiting tourist get new rack mounting brackets welded at a friends fabrication business. The load the tourist was carrying was too much for the standard parts kit at most bike shops, so I am glad I could connect him with a place that could do the work.
Perhaps as this develops, it could be extended to include "sponsored services". Essentially hyper-local service business directory who are touring cyclist friendly. Not sure how the vetting process could work but I'm thinking that if done in a good way could be a win-win for the WSL (sponsorship revenue potential) and the touring cyclists (vetted businesses that gain reputation).