Let's just think about this for a moment.
* A fixed up Reborn city is already such a nightmare to sprite that Ame's only gonna be able to throw that in E16 along with new animations. What makes you think that she'd even want to sprite the entire Heart Gold/Soul Silver (2 regions + a lot of cities/caves/routes/.... and Mt.Silver) ? Even if there's not copyrights involved, no one will ever want to sprite the whole damn thing.
* Reborn is known for its dark atmosphere, and you want to bring the joyful atmosphere of the main series (which everyone dislikes because of the boring story and the non-existence difficulty) into it ?
In my opinion, if i really wanted to return to the 2 regions, i would just go back and play HG/SS on emulator and call it a day.
EDIT : If you really want to talk about Pokemon in general, we have Pokemon Fan Club and Fan Game Expose for that purpose. The whole Reborn tag is only for the Pokemon Reborn game.