Before this becomes another dissertation on “which dragon should fill Big D’s Shoes”...
The concept of the Elder Gods being used as an inroad for the re-insertion of the Horroi plotlines seems doable and plausible, I just don’t want SR to devolve into a CoC world. Dystopian Cyberpunk Paranatural Fantasy ... fine. I would point out that references to Al-Azif (the text) have been made in Sr books in 5E, so this does open up inspiration from any number of sources.
HMHVV ties to the Elder Gods I personally believe are because Blood Magic, of any kind, is an easy method of channeling higher than normal levels of magical power, and with the global tainting of the mana sphere due to the GGD these options are more center stage for usage. I would however point out that willing sacrifice for Blood Magic is a slightly different ‘flavor’ to the Magic, regardless of outcome. This may have even longer reaching effects than just attracting the attention of Elder Gods and Vampire Cults.
As for Dragon references;
* Ghostwalker (Dollmaker/Icewing) is not in favor of metahumanity and frankly shows signs of madness and or senility IMO.
* Schwarzkopf, is an interesting option and has not made many, if any, matrix appearances in the main or core sourcebooks.
* Arleesh, another option and an admitted personal favorite of mine own, might have the interest but she has also shown to be on certain levels to be something of a traditionalist. As she is described as “young” in the scale of Great Dragons, she had a significant place in Big D’s mind because of what she is doing. Certainly a protector of the ‘lesser races’.
* Hestaby/Orange Queen ... a definite contender and while she may not be “an insider” to the Dragon Political Scene, she is still a force to be reckoned with and even Lung gave her a small token of respect in regards to her command of ritual magic. She also has not stopped her access to the Matrix, which has me considering the options and methods she is using for such talks.
* Celedyr/Script Diver, as the current Loremaster he has the political clout in Dragon society but if he tinkers around too much the Corporate Courts may decide to have him pay full or greater prices for all the CFD/Boston crap that he certainly is involved in.
* Lofwyr, uhm... he’s watching but I think he’s focusing on his own “kingdom” at this point still, especially with MCT at the top.
None of the other Greats have ever really been that involved, except Masaryk whom I left out because it is known he was doing some “Wyrm Talk” episodes, but that hasn’t been mentioned or updated in the timeline for years, both in real time and game timeline.