A LoyaltyLobby reader sent me two links to recent articles on Bangkok Post (one of the two English dailies published in the city) regarding flight cancellations and order of not to market flights between Thailand and Japan past May 31, 2015.
The restriction all stems from the audit that the ICAO did (read more here) that found significant safety concerns how the airlines were overseen by Thai regulatory authorities. This may result other countries to restrict the operations of Thailand registered airlines.
Six airlines have been ordered not to promote or sell any flights to Japan after May 31 in case the flights are cancelled due to safety concerns.
Japan agreed to allow Thai-registered airlines to resume flights to Japan from Saturday, running until May 31.
Whether flights to Japan are allowed after May 31 depends on whether the Thai airlines in question can improve safety standards in time.
The six airlines operate scheduled and charter flights to Japan and consist of Thai Airways International (THAI), NokScoot, Asian Air, Jet Asia, Asia Atlantic Airlines and AirAsia X.
Japan imposed a temporary ban on the six Thai airlines over aviation safety concerns raised by the International Civil Aviation Organisation (ICAO).
The Thai government is probably trying to address the issues found by the ICAO audit to prevent Thailand registered airlines not being able to operate foreign routes. This is serious considering the tourism inflows to the country.
So, if you are considering booking flights to/from Thailand to other countries, it probably would make sense to avoid Thailand registered airlines for now until the ICAO issue is resolved.