I think there are some countries that are unvisited and safe to be visited: (Only apply for US Version)
EuropeAndorra (Combined with leg in Spain and/or France)
Bulgaria
Cyprus
Former Yugoslavia Countries (Eg. Slovenia, Bosnia & Herzegovina, Macedonia, Montenegro)
Latvia
Luxembourg
Malta (Will be visited in TAR25
)
Monaco (Combined with leg in France)
San Marino/ Vatican City (Combined with leg in Italy)
Slovakia
AsiaBahrain
Qatar
Nepal
Bhutan
Myanmar
Laos
East Timor
Maldives
Africa (Highly doubt with the visit due to unknown safety reason)
Comoros???
Eritrea???
Djibouti???
Zimbabwe???
Mayotte or Reunion (part of France)
OceanicSamoa
Fiji
whatever island in ocenia has not been visited
Americas & CaribbeanHonduras
Nicaragua
Dominican Republic
Barbados
Trinidad & Tobago