Alas, I think you need to treat access defaults (internationally, nationally and regionally) with a huge pinch of salt.
As an example, the listed access defaults for the UK is wrong because legally there are no access defaults for the UK as a whole (they vary by country, and are unrelated to any OSM main tag). Once you get into “unusual” modes of transport you get into legal exceptions and edge cases, and an app provider needs to ask themselves about local law, not the OSM wiki.
Even in “right to roam” jurisdictions like Scotland, where you are allowed to walk / cycle is described by rules independent of any OSM tagging. You can guess, but it would only be a guess.