So that's an interesting chain of thought.
I don't think anyone claims that Ross 860 has or is Raxxla. There is some stuff worth investigating.
Do you happen to have a reference to anything that confirms that Gamma Velorum is the Guardian homeworld?
The permit lock over the Regor Sector seems far too small for something as large story-wise as the Guardian homeworld. And putting Raxxla there contradicts the claims that Raxxla is reachable (which it may not be, but then again, if it's there, it's not interesting from any current point of view since it's not something you can in any way confirm or reject. There is no point investing any time in "God theories". It's the same situation as speculating that Raxxla is in Polaris.
The reason I'm asking though is because Velorum constellation is heavily duped in the galmap - many stars have two systems with their name. One of my next activities is going to be to use what I learned in NGC 188 and see if I can fully remap Velorum (and perhaps Cancri) to alternative set of coordinates / systems based on their existing duplicates, and see if this turns out to be something useful. So that would mean that there is somewhere (perhaps unnamed) Gamma Velorum duplicate that we most likely
can visit.
BTW, we still don't know why @Reyedog can see duplicate AH Cancri and most of us cannot. It may be a bug, but based on what I've seen those duplicates are entirely on purpose. Maybe you have to go near this to trigger the mechanic?
Actually, turns out we can - it has the same mechanic as the duplicates in NGC 188 - only one of them is visible in galmap search box results, but the other one is still there.
I doubt that them fighting us has anything to do with Guardians. In fact, based on the lore, they probably didn't even care about Guardians, they just happened to collide with each other for whatever reason just like humans did. The lore in game makes it abundantly clear we gave them enough reasons ourselves to come after us (the mycoid virus being #1), so I don't think we need to look very deep into this. This tags on to the "dark ending" of FFE. What happened before that is unclear from Elite Dangerous perspective, but some of it is described in the codex - so we don't have to try to reinvent this. According to the basic lore in the codex, Thargoids attacked Guardians because Guardians developed into their resource territory (aka nebulas with barnacle sites). Literally the same concept applies to humans and that is what this whole thing is hinting at. The next entry explains who and why get nuked by them after getting hyperdicted.
You can speculate other things, but that's going against basic info given to us in the codex so it's inventing alternative narrative not actually consistent with the game.
The real question is why the titans and why the whole thing with Sol, but I honestly don't want to read too much into this, and unless we find Raxxla in SOL and it happens to actually have anything to do with Thargoids, I think we can ignore that entirely.
After some thinking, I believe the problem is opposite to what is being assumed here: it's not whether Thargoids know about Raxxla, it's about whether Raxxla connects to Thargoids in any way, and we have no way of knowing that unless we find Raxxla. It's unlikely analyzing Thargoids will tell us anything about Raxxla simply because of the communication barrier (unless we somehow find a diagram or map in Thargoid artifacts or comms that leads us to Raxxla, but that hasn't happened yet so I'm not holding my breath - it's worth checking those things just in case, but I sincerely doubt it). Going to Thargoids for that info is also a very roundabout thing - the chief speculation is that some humans know where Raxxla is so why bother going to Thargoids for that info - there is no reason to.