I'm curious about that too, but looking at how Chaquino writes his routes I think I understand how it may happen.
In one of the devlogs, there was a preview with a bartender saying "courtesy of the gentleman in the corner" and Riley and another girl are shown sitting at a bar. And in Chapter 3, if you are supportive of Zeke, the MC says: "We should go for a beer one of these days".
So my guess is that they end up meeting at this bar, but if you choose the other option, you probably don't even go to the bar with him, so we can completely miss the chance to meet Riley as a whole.
That's my guess at least...