Disclaimer I don't know much about game engines and some of these features may already be achievable in UE4 so plz don't roast me to much 
.
Imagine how beautiful ManEater 2 would run on UE5:
*Environments could be more reactive for ex. sand can get kicked up and float around until it dissipates or if your shark is on land for to long you can get mud covered on you until you get back into water. Fog can linger on the surface of water and you could have bugs floating around. Also on a newer engine you could have bigger shark sizes, bigger boats, bigger more densely populated maps with more fish species in each map.
Some destructible environments like underwater research facilities, massive oil rigs, big cargo ships, and bridges that can all be destroyed when your shark is fully grown.
*Ray tracing would drastically change how the lighting looks in the game and could be a great addition depending on the hardware the system is running on.
*Dynamic weather systems could allow for flooding, fog, overcast days could equal less visibility underwater for Bounty Hunters making it easier for you to evade them while sunny days could provide more visibility making it easier for you to spot.
*More Dynamic sea life for ex. at the bottom of the level you can have fish that are more bottom feeders and only spawn near the bottom of the map and other fish that hunt towards the surface. Fish will attempt to flee when they get critically injured.
. Imagine how beautiful ManEater 2 would run on UE5:
*Environments could be more reactive for ex. sand can get kicked up and float around until it dissipates or if your shark is on land for to long you can get mud covered on you until you get back into water. Fog can linger on the surface of water and you could have bugs floating around. Also on a newer engine you could have bigger shark sizes, bigger boats, bigger more densely populated maps with more fish species in each map.
Some destructible environments like underwater research facilities, massive oil rigs, big cargo ships, and bridges that can all be destroyed when your shark is fully grown.
*Ray tracing would drastically change how the lighting looks in the game and could be a great addition depending on the hardware the system is running on.
*Dynamic weather systems could allow for flooding, fog, overcast days could equal less visibility underwater for Bounty Hunters making it easier for you to evade them while sunny days could provide more visibility making it easier for you to spot.
*More Dynamic sea life for ex. at the bottom of the level you can have fish that are more bottom feeders and only spawn near the bottom of the map and other fish that hunt towards the surface. Fish will attempt to flee when they get critically injured.
hopefully some of them are implemented
and I agree I feel like the very talented team at tripwire would just have a field day when it comes to making a sequel on unreal engine 5. And I agree hopefully in the sequel they can add a dynamic ecosystem that hunts humans and other fish