I initially thought the same too that the ending 'thing' was whatever the void + Godseeker came out to be or a scarier us, and that it came to Hornet.

But rewatching the scene, hearing chains and then the bottom of the head is pointy (like Hollow Knight's head). Highly highly definitely probably HK. Hornet doesn't know whats going on, so upon seeing HK wander out of the egg, she's going to be apprehensive. >! (If he's an ally in Hornet campaign I'll scream).!<

And this is just my take on the ending. I think Godseeker wanted the void god like you said, idk if they welcomed it once they realized that they're done for though. Their whimpering (out of awe? fear? both?), the music, their reaction to the void consuming them in the physical world lead me to believe it was tragic for them. I feel like after Godseeker experienced such a catastrophic event wherever the Land of Storms took place, that they just want to worship, not to get consumed/or die. This could just be me liking a "got more than you bargained for" story too, and maybe they have their own weird definition of worship.

I haven't sat and thought about all the dialogue and lore we got this DLC though so, take this theory/take with a grain of salt.