Deleting the game’s page and recreating it serves no benefit. When you make a major update for a game, you can make a devlog marked as such, and it will bump the game in a similar way new games are.
As for the views/download ratios, I can’t say for sure. I’ve published a game to both Itch and GameJolt (I assume that’s what you meant by GJ) and had more success on Itch. You are quite likely getting more views because the game was featured, and not because “you did anything right/wrong”.
I don’t know the process on GameJolt, but on Itch, it is decided by specific members on the team what game is going to be featured, and the only thing we can do is keep making fun games and hope it happens sometime.
Congrats on getting featured :)