One word names especially those which have "meaning" in language are tougher to trade mark - "Surprise", "Firefly" - not impossible just harder. Hence the sudden "Twilight Sparkle", "Fluttershy" - essentially words or word combinations that dont mean, dont represent anything else. I am not saying this is the case for every character just the reasoning behind a lot of them [Lyra Heartstrings? Trixie Lulamoon?]. The glaring contradiction of course being Rarity.
I wonder if this is why she was often referred to as "Rarity the Unicorn"--could using the whole phrase have made for a stronger trademark? (In addition to "Hey everyone, G3 has unicorns now!")
I also wonder if this would make it easier to bring back any G1 names that were more than a single word or common phrase.
Actually Twilight Sparkle started out being called "Twilight Twinkle" which was a G3 name. On the Hasbro tour at the 2011 Fair, they had some early design sheets out for the mane G4 characters. Twilight Sparkle was named differently & her color scheme was darker, resembling Luna's color scheme. There was no explanation for the name & design change, and I doubt that many collectors would know that unless they were on those tours & happened to flip through that stack of drawings.
Ah, really? I only knew that she resembled the first Twilight from G1 at one point, so I simply figured, "Twilight + Princess Sparkle = Twilight Sparkle"!