<p>Since there is no answers and not much comments, while the question and pro-tag comments received several up-votes I would consider creating the tag. Let's wait for few more days if anyone disagrees (please comment and/or down-vote this answer if you do). If there would be no disagreement about it I'll create the tag and add it to the already existing questions.</p>

<p><strong>EDIT</strong>
I started re-tagging from the highest up-votes questions. Check <a href="https://stats.stackexchange.com/questions/tagged/birthday-paradox" class="post-tag" title="show questions tagged &#39;birthday-paradox&#39;" rel="tag">birthday-paradox</a> tag.</p>
