No, that is an assumption based on nothing.
I am saying you cannot call a search for the dark kingdom or senshi part of canon when it is not shown in canon.
Canon cannot include stuff not written or depicted in the source material. Such a search in this case is mere fanon speculation.
Even author or creater statements after the series run in interviews are merely author intent.
Had the authorities been THAT stupid, they would have deserved having Beryl as their new overlord dictator.
For doing their job? Mind you, I am not saying they would succeed or not, I am saying such a search would be in their duties.
For all the romantic overtones and depictions given the story. The sailor Senshi are really people living in Japan whom have sworn fealty to a foreign power, and are operating as law when they have been giving no such authority or mandate by the Japanese government, the essence of being a vigilante.
Look, people are being hurt in the streets, international incidents have occurred, and terrorist threats have been issued, major property damage has occurred as well, and even if the senshi are 100% innocent the government is going to want to know what exactly is going on. The senshi are one of only two parties that could explain it to them.
It may not be canon, and merely fan speculation, but the government has a duty to look into this and hunt all parties down. And that would be the case whether Japan, China, France, or the United States.
To believe otherwise is stupid. Even if as said it is not canon that they did so. And thus also goes to my statement that shows like Sailor moon break badly when analyzed, because it makes government look stupid or not following through.