I don’t think a wiki page can automatically evaluate the completeness of a route relation, even if it has been tagged with the total distance. I think it relies on someone editing the wiki to check with one of the relation analyser tools what the current length is and do the maths themselves before updating the page.
I suppose it might be somehow possible to write your own program that calculates the completeness and then somehow automatically edits the wiki page for you, but that sounds like a lot of work.
You can downlaod the source (in Perl) or ask the maker to run the check on an area you are interested in. Germany and The Netherlands are already on a regular basis evaluated.
If you are able to run the Perl programme yourself, it would be appreciated if you share the results on a wiki page.