There is component named Text in my project. ESLint doesn't tell me that Text is undefined because it's existing class in the DOM API.
I suggest add rule which deny use components defined globally:

{
  "rules": {
    "react/jsx-no-undef": ["error", { "onlyImported": true }]
  }
}

import Text from './Text';

<Text /> // ok

<Text /> // react/jsx-no-undef: 'Text' component not found in current scope.