I remember maybe five years ago on the Sideshow board, there was a thread talking about potential Predator weapons and I said eventually the Predators would have some kind of tracking animal. I got promptly laughed at and told my ideas were stupid and that those concepts would never make it into a film. My argument then and now was always that the tendency of sequels, any sequels, is to keep upping the ante and show the audience something different. P2 had a throwing disc, spear, net gun that were all new weapons. AVP got the additional forearm blades and ankle knives. Wolf got a double cannon and whip and a cleaner kit. And yes, the new Predators got not just one, but two type of "tracking" animals, the falcon and hunting dog thing. Also Berserker had a quasi rotating plasma cannon ( kind of like a slow gatling gun)
There are only so many weapons or gear that you can outfit onto a character, make somewhat plausible and offer something different to the audience. To me, the Predators sequel, the Predators there will have something different in their loadout.
A jet pack doesn't seem so out of the realm of possibility in my book. My issue is always if it can serve the story first, and not have the story wrapped out showing off special effects and CGI.
My guesses on new weapons
An archer Predator, some kind of bow and arrow system
A Predator with a battle axe.
A Predator with a shield.
A Predator would a shoulder mounted rocket launcher system ( kind of like Iron Man 2)
I'm sure some people will laugh like they laughed years ago, but where else can new producers and directors take the film series? You interest fans in part by showing something new.