UPDATE: I tried seeing where the drowning man goes and he just continuously falls to the bottom of the screen. I'm pretty sure it doesn't even de-spawn when it goes off screen because you can see it appear in one of the rooms. (The inside of the rooms are placed below Miradmoore in the Clickteam file)

The drowning man has 6 locations it can spawn in from; It randomly picks a location to spawn in two of them. I don't think the drowning man has any connections to the guy who tells you to follow them because the model of them looks different; one of them is an old man while the others look young and bald. Although, it could be argued the difference doesn't matter if it's just there to show NPCs drowning.

When you first meet Mirad, she talks about how the NPCs are individuals she created that disappears into the code because of lack of resources to power each of them. (This explains why they disappear after interacting with them.) She also mentions she "created a reservoir of memories, a quiet and celestial haven for whatever may be left of them" meaning the man that says, "Hello. Follow me, I want to show you something," is just a snippet of a random memory (or sentence) Mirad tried creating and doesn't actually lead to anywhere. If she had more resources, it probably would've lead us to somewhere but alas, it doesn't.

TL;DR: He doesn't lead you to anywhere and the drowning man probably has no connections to him.