I upgrade my Ember app to use the latest commit on the master branch of ember-radio-button to remove all the deprecation warnings. It seems that the latest code on the master branch no longer sets the aria-checked attribute.
{{! component usage }}
<RadioButton @value='yes' @groupValue='yes' @name='response' />
{{! `master` branch rendered HTML }}
<input name="response" type="radio" value="yes">
{{! version 2.0.1 rendered HTML }}
<input aria-checked="true" name="response" type="radio" value="yes">
I've reproduced this issue with both an Ember 3.28 app as well as a 4.1 app.