#3 To have a Chyna-Beth Phoenix-Kharma-like moment
When Nia Jax entered the Men's Royal Rumble match, she became only the fourth woman to ever enter a Men's Rumble match. Prior to her, the only women who entered the Rumble were Chyna, Beth Phoenix and Kharma (Awesome Kong).
What all four of these women clearly have in common is that they were dominant superstars. They would rack up eliminations and etch their place in history. Mustafa Ali was having quite an impressive showing at the Rumble and looked like he was going far until Nia Jax threw him out.
Since these moments don't happen very often, it's likely that we won't be seeing anything like this for a long time now. WWE likes doing this generationally, and the next time we see a dominant female star enter the Mens' Rumble, it'll likely be years later. For now, it's better if WWE chooses to focus on the Women's Royal Rumble and its importance.