Would you register (name, email and country) to play an adult game?
Absolutely not.
Would you like to receive a game update in a single installation instead of having to download the game whenever a new version is released?
It depend.
With Unity it would be possible to do these two things, but not with Ren'Py, because Re'Py today has no "connection" to the Internet and has no intention of having that in the future.
Well, perhaps should your colleague and yourself start by learning the subject before debating about what engine would be the best to use.
Ren'py have a
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that permit you to update the game from a distant website, and it's far to be something new since it was already present in the version 6.14, released 8 and half years ago. It's not used because it need a website, and don't really works well with a Patreon-like business model ; you need to link the game or the hosting site to Patreon in order to limit who can download the update, what is too much of works for indie devs who don't know much about codding and networks.
Ren'py also come with the default Python modules, so it's perfectly possible, without any addition, to make your own login feature ; a site that distribute Turkish translation add such process in top of their version of the games. There's even a game (now abandoned ?) available here that include a quickly wrote chat feature.
So effectively, there's no intention to add Internet feature into Ren'py in the future, but it's because it have them already since at least near to a decade.