Well looking at how TAR is cast. They look for an older team, a minority team, at least two all female teams, at least two all male teams, a comedy team, a handicapped (hate the term sorry) team, siblings, parent/child, a fighting couple team and a gay team.
Thats generally the cast of TAR (And it also applies to the two editions that featured returning racers.
Some groups get a huge advantage, one because of available options. There aren't for example a huge number of minority teams, parent/child teams, old teams, competitive female teams.
They would not pick (though I wished they would the best teams). Hell they haven't even picked the best out of the categories they normally choice from (which I would like as well).
Based on typical casting. I would say out of this group Bill & Cathi would have a strong chance if they were still interested and it didn't happen 10 years from now. Just due to the number of good older teams is few and far between.
Average couples are a diem a dozen (based on the number of them and they typically race well). Andy & Tommy might have a chance if the producers consider alpha male teams (they wouldn't in all stars, which is just beyond stupid) as tehir hasn't been many cast since season ten. (I can only recall four teams really fitting that title, Sam & Dan, Cowboys, Trotters, and Andy & TOmmy since season 10).
Female teams are also hard to cast, because in general they don't last long.