Yes, it is true that despite fears that Japanese Americans would be disloyal, only one Japanese American was ever convicted of treason against the United States, since much of the paranoia over the domestic Japanese threat was due to racist views, not rational thinking.
A lay brother who escaped from the French invasion warned missionaries in a near by mission about a possible invasion. They overreacted and thought they needed to replace the missions they could lose and sent Marques de Aguayo to create Los Adaes and La Bahia.