Here's the prediction post here.
Let's see how correct I was.
WARNING!! SPOILERS FOR CHAPTER 5 AHEAD!!
Well, I was almost correct? Flowery WAS the name Papyrus often called Flowey so yeah, I'll take it as a win! :D
You know the yellow Flower in Asgore’s garage? The one in the center of the rest? I think that Flower specifically will have been nicknamed “Flowey” by Asgore.
I got the name completely wrong though. I'm taking the L for this one lol.
As for his role in the game, I think he’ll be a penultimate chapter boss. Considering Flowey is smack dab in the center of of the garage, I don’t see him being a secret.
YES I KNEW IT I KNEW HE'D BE THE FINAL BOSS (this was before I knew what the word penultimate meant I thought it meant final 
)
As for my opinion in general on Flowery...
Well, I won't say I hate him, but he's definitely not my favorite in terms of the seven colored Flowers. He DID get Ralsei the closest to an actual crashout though, and for that, I'm grateful. But GOOD GRIEF he was annoying in the beginning.
Anyways yeah that's all :)