Furthermore Rock’s full name is Rocks D. Xebec and Blackbeard’s ship is called the Saber of Xebec. This doesn’t seem to be meaningful initially but upon hearing the name of Rocks it is alarming.
Rocks D. Xebec has basically been wiped from history with the exclusion of memories from older Marines so there is no way Blackbeard simply studied him to acquire the ship name. A coincidence also seems far to unlikely. A familiar bond would be more likely and more logical.
Both the acquisition of the island and the ships naming could be Blackbeard’s act of honoring his deceased father.
This as well as his dream ideology, being a D. Clan member and the overall similarities that he seems to have to Rocks description makes Blackbeard seem almost identical to the modern day version of Rocks.
When the Marine executed Gol D. Roger, anyone known to him was also being hunted down, especially with the rumours of him impregnating a woman, there was a search for the woman. Likewise I think after the fall of the Rocks Pirates, the Celestial Dragons ordered the Marine to search for any blood related heir to Rocks D. Xebec and to execute them. So like Rouge changed Ace’s name to protect him from the Marine, is it possible the same could be said about Marshall D. Teach?
*Theory by SossaaSharingan