Ok I on my S8 now I will look for this I did not see it right away but have not look to much. But right now they already have a Update out now that's a little over 389Mb so I will check again after the update..
The answer is NO, it does not have RCS enabled, as its using TouchWiz Messenger app & the Carrier Services app from GPS isnt yet updated from Sprint & Google to enable this on this 3rd party stock messenger app.
Also, Its REALLY elementary of everyone who doesnt have the phone or the knowledge ti keep posting these 'answers' like 'This is what is says about an S7 that's over a Year old'. Come on.
You have individual features that can be turned on and off that are part of the Enhanced Messaging feature, here is a pic for them
Yes the S7 as far as settings are real similar to each other so Galaxy devices are just that especially when they are running the same version of Andriod. The main diffrence with the S8 is they just combine things that the Note can do and the Edge all into one. There will be a few things that the Notes can do a little diffrenet from the Galaxy devies but not to much.