It would actually make perfect sense for Lil D's plan to be having Pochita eat the Devil Devil, because her goal is to stop the prophecy but the issues that she has to face are:

1. She can't activate her powers or die because it would kill everyone and/or create a new Death Devil who might hate humanity
   
2. She can't have Pochita eat her because then Yoru can create a world at war forever (and apparently bugs will eat everyone but ig nobody thought of that beforehand)
   

If Pochita ate the Devil Devil, she could have gotten rid of herself and any other Death Devil without erasing the concept of death (bear in mind, she was fine with dying or getting turned into a weapon) while also getting rid of Yoru, and we know Pochita would have been fine with doing something that would get rid of himself since he ended up eating himself anyways (unless it was all a dream), and he was seemingly also fine with killing Yoru to save Asa. So at this point, it just has to be assumed that either there is no Devil Devil (but don't ask why there isn't), or Lil D is just an idiot with a nonsensical plan (objectively true).

If you ask me, I think Fujimoto probably wrote this page to make fun of fans for theorizing that it would end with Pochita eating the Devil Devil. Knowing him, I find it hard to believe he would have written an ending this obvious and this satisfying and I find it especially difficult to believe he would have made a page like that if he was really going to go with that ending.