Given that Legends of Tomorrow is fundamentally an ensemble series, that title sequence flashing through a whole bunch of superhero emblems always made sense.
Arrow has aways been about the guy in green with the bow who, you know, fires arrows.
The update to add the symbols of the other members of Team Arrow probably means that Arrow is going to feel like much more of an ensemble in Season 6 than ever before.
It was likely that the side characters would begin to get more time on screen as soon as Oliver’s flashbacks ended, but I don’t think many fans expected Arrow to go all the way of adding Black Canary, Wild Dog, Mr. Terrific, Overwatch, and Spartan to the title cards.