Currently the only places to watch the fireworks will be from the restaurant and from your hotel room, as long as it’s facing the correct direction.
I think because of this, in the future the Riviera will separate its preferred rooms into “Fireworks” and “Pool/Caribbean Beach” views. Similar to what they did with separating Boardwalk’s rooms into Boardwalk view and Pool views.
I also think it’s likely they will add a viewing area to the top of the resort closest to the fireworks similar to Bay Lake Tower’s Top of the World Lounge. If you look at the hoteI’s setup the wing closest to the fireworks is 1 floor shorter than the rest of the resort. I think this was done on purpose to allow for this potential future addition.