According to the most severe predictions, 90% of the world’s languages could disappear by the end of the century. This is an example of

Endangered language or moribound languages

Explanation:

According to the most severe predictions, 90% of the world’s languages could disappear by the end of the century and it is an example of Endangered language because endangered languages refers to languages that there is risk of reduction in usage because the native or speakers die or they switch to speaking another language. This occur when the language has no more native speakers and due of usage.

i believe this is