It depends I guess, a game like Dark Souls could feel emptier.

RPGs are generally not as popular as whatever pop culture game wows the masses anyway. The most disconnected I've felt is when I venture slightly outside of RPGs and Tactics games is when I play Souls games because of their semi-multiplayer aspect. Thankfully, because Souls games have a cult popularity, and the fact the Fromsoft support those games longer than normal, people still play those games and you can still enjoy the semi-multiplayer aspect to an extent. The remaster/re-releases have helped.

I don't think there usually is an inherent benefit or detrimental quality to playing a game "late" or "on-time". This is probably helped by the fact that games are being preserved now more than ever and even if they are rough around the edges you can still generally play them. However I will say that if anything, I would think there's usually a detrimental quality, because you'll occasionally find that you're more excited about the game because of what you can possibly talk about, rather than how good it is long-term.

Either way I feel like most semi-popular games have fairly active reddit communities, so if you feel like discussing Undertale you could probably do that there.