If orcas live for decades, have memories, and have language, then they're telling each other stories about us. The Southern Resident Killer Whales are down to 70+ beings. They've probably figured out by now that humans are the ones responsible for their food supply getting decimated. I suspect orcas everywhere are trying to figure out ways to communicate with us and are doing an amazing job.

They probably haven't accounted for human denial and human-centric science. These two things lead to scientists being like "Gee! I wonder why they're parading their dead babies and carrying them around? They must be grieving!"

As opposed to a slightly more realistic interpretation:

"They must be grieving and are trying to tell us 'See what you're doing to us?'"