So I actually tweeted Craig McCracken on a Question that people never thought about asking him? Please do Read.
So I had a conversation with someone on that beautiful art showing off the ppg and rrb of different skin tone and culture as well :0 if I'm correct(?). And what this person had told me was that the episode that almost every ppg shipper loved, 'The City Of Clipsvile' was made, because it was demanded by the entire fandom that loved ppg x rrb -so Craig made the episode happen but instead he made it to mock the fandom. That's what this person told me in their defense towards why they think that ppg x rrb isn't canon at all -that the episode isn't canon what so ever ...yeah, -I mean I can legit show screenshots, give me a sec. -Here is our entire conversation -mind you I believed them because of the fact from the wiki page of the Powerpuff girls -this also proves to show that you really shouldn't -again believe what the wiki can say about shows, -even fandom ones. Because sometimes they can be legit wrong.
But onwards to the screenshot;
oh and if you want a better view of the screenshots here: https://imgur.com/a/Oc9hbtd do tell me if the link doesn't work!
So after I replied my 'finale' response, I didn't really think of it much because ya know what the wiki is correct...until I doubted it, and like I stated went on to ask Craig a question -basically I asked him if it's true what the ppg wiki said on it's fun facts which was this;
The thing that surprised me the most was the fact that this man legit responded to my butt(just an expression when I used the word butt on my text. what I meant is that; he legit responded towards my butt -it's just another way of saying he responded to me)-i usually have terrible luck trying to contact creators to ask them questions that I wish to know. But this threw me off xD. I was so happy that he responded back , and grateful to know that the ppg wiki fandom page needs to be updated on that fun fact, and to stop spreading false information because the real reason why Craig made that episode was because;
But yeah @fulminare here is the actual truth behind that episode xD it wasn't to mock nobody :/ or the negative assumption you thought of -just like ppg fandom page implied of. the episode was made for fun, simple as that :v. But again still proves to show that the episode is canon :3. And that ppg x rrb is a thing in the show lol. And that Craig was still working on the ppg.