Team Arrow is at a bit of a crossroads leading into season five. There was enough death to go around in season four, and it's affected the team significantly.
Now it's about picking up the pieces, but fans can still expect the death of Katie Cassidy's Black Canary to play a big part in the character arcs throughout the new season. That said, there is still one big mystery surrounding the fallen hero that needs explaining, and that is what she told Oliver right before she died.
"We're as curious as you are, but the good news is, the wait is almost over. According to Mericle, the late Black Canary's last words will be revealed in the season premiere."
At least it won't be six episodes in until we know what Lance's final words, which would just be cruel, but not unheard of.
In the same issue, show creator Marc Guggenheim was asked whether Cassidy's newly free schedule would allow her to appear on Arrow's sister show, Legends of Tomorrow. His answer was a bit cryptic, but ultimately it doesn't look like she will be making an appearance.
"No, that conflicts with other plans we have...he said, intentionally misleading and hopefully teasing," Guggenheim says with a laugh."
The most I can extract from that is either they have Arrow-centric plans for the character still, or that it means Black Canary will at some point be appearing on Legends, but just in a different way. Of course, it could mean none of that, but hey, speculation is fun right?