So, yes and no. I think that depends on how close the adaptation is going to hew to the original work.
For the Marvel Cinematic Universe, for example, what they do is only a very loose adaptation of the original comics. Referencing the comics in discussion may be amusing, but usually doesn't give away anything about the plot of the work. In discussing the upcoming Wheel of Time series, I expect discussing the plot of the book is very likely to give up elements of the TV series.
In the end, this is really a Golden Rule question. We are talking with actual people, and we should have sufficient respect for them to not ruin their experience because we are thoughtless or showing off how much we know about a source material.