Odyssey is a long ways off yet. I don't like this, "We're abandoning the game you already own in order to make a game you'll want to buy a year from now" approach. It's not just Galnet and CGs either, but the entire Thargoid invasion just ended in a whimper. Even LOST had a better ending than the Thargoid story!
I'm definitely not happy with it either, and said as much at the time of the original announcement, but they're clearly not going to change now until after the release.
One of the big problems with Elite Dangerous from day 1 is I think Frontier never really appreciated - and none of the relatively small band of enthusiasts chatting around pre-release did either - just how much their processes were going to have to scale up to support ED actually being a success, or being run for multi-year terms.
So things like player groups submitting CGs sounds like a great idea (and in the early days
was a great idea!) - takes some work away from the writing team, lets people achieve something a bit more personal but still with a permanent effect on the galaxy, etc. - right up until the point where there's several thousand player groups, they all want one, and someone has to filter through hundreds of submissions a week looking for the interesting one.
(See also: player-submitted Galnet, PMF insertion, etc.)
My understanding is that setting up a CG at all requires a lot of technical work, presumably because the original ones were brought out quickly in 1.1 to add some early story capability, the expectation was that Powerplay in 1.3 would mostly supplant that with something that was much more scalable, and then by the time it became clear that wasn't working and they went back to doing more with CGs, there was never time to make them more scalable.
As others have said, a proper "DM" interface to allow non-technical staff to set up a lot of this stuff would be incredibly useful for them. But developing it is probably much easier said than done.
Thargoids I think they're in a particularly tricky position on, because things like IIs and a lot of "human" stories can be told entirely with existing assets and capabilities used creatively, whereas the Thargoid story can't really work like that. The next stage of it can't just be "Thargoid Interceptors, but in a different system this time".
So that's probably piled up in a huge backlog of art assets, AI work, and so on, but they don't really have enough of those just yet to tell an interesting long-term story with what they have. That basically ties steps in the Thargoid story to major releases, which are years apart, which makes it very hard to develop.
