Yes, much of the time. If the etmology of an RPG is understood and encompassed/particularly present in a game, then it is especially important. If someone knows the etmology of an RPG, it can make it much easier to feel more "into" the game and also gives a feeling of continuity and depth beyond what is just presented there. It establishes the universe beyond the game often times.
Knowing the origins of any word can give you important insights into the reasons for the existence of the word, and the connotations it is meant to carry. Knowing that RPG has Russian roots rather than English roots gives you important perspective into the origins of not just the word but also the device. In the end this gives us a greater, albeit marginally so, understanding of the nature of RPGs.
Blending elements of the two doesn't mean that there aren't substantially different conventions between them. Most people call Fallout 3 and New Vegas RPG-shooters, because they blend elements of both genres. Destiny is a shooter with RPG elements. The notion of WRPG-JRPGs wouldn't sound that absurd if they weren't both described as RPGs. I think if the naming conventions were different, things would be way less confusing.
It might be interesting to know the etymology of RPG's but it is not necessary or particularly important. It could be helpful when playing an RPG to know these things, but it is just as much fun and just as easy to play the game without knowing these things. The vocabulary and strategy is helpful, however.