Athrun and Cagalli at the end of Super Robot Wars V, a video game series incorporating characters from all kinds of Gundam and Mecha shows. The games themselves are very strange since you see Athrun and Kira interacting with the Gundam 00 characters, the Cross Ange characters, etc. But the creators of SRW are known to do the characters of Destiny (especially Shinn) justice in terms of characterization. With regards to Gundam Seed/Destiny and the CE universe, SRW V takes place after the events of GSD (though a different version since Shinn was fighting Celestial Being as well as Orb –> See SRW Z).
This game came out on February 23, 2017, so it shows that even after almost 13 years since Destiny ended the creators of this game know that Athrun will always go back to Orb to be with Cagalli.
Part of me isn’t sure what Athrun means when he asks Cagalli if she think “it’s hopeless” Do they mean maintaining the peace in Orb and the SRW universe? Are they talking about the two of them? Personally I think it’s the latter since they moved on from the talk about peace when Athrun asked Kira what he was going to do and Kira said he was going to travel the world (with Shinn apparently since Athrun isn’t coming).
Either way, this is nice as an Asucaga shipper after 16 years when Gundam Seed Destiny aired. Many of us have read comments from the director, official music videos, and the new remastered scenes (or Final Plus and Special Editions) that point to Athrun returning to Orb to be with Cagalli. However, it’s nice to see them interact after GSD too, even if it’s not officially canon (the only post GSD canon anyways is an Astray manga and the little notes on Gunpla Kits anyways! So frustrating!)
Anyways, if they ever make the Gundam Seed movie please have a solid team of writers and directors to help Fukuda out. Maybe make Fukuda the executive producer like on Cross Ange.