We do have new stuff. Today we had new logs and lore things. A cg past week. A stream every 2 weeks.
There's stream every 2 weeks where there were 2 streams a week, which they said is for the better, because... less is more (not that I disagree - those streams were seriously lacking meaningful content).
But they said almost the same thing when they switched from 2 streams a week to 1 stream a week just few weeks before that - it's for the better, they will have more time to prepare more meaningful content, etc. Everything they drop - they make it sound like it's for the good of the game and players. Rejoice, we now have less streams, but those that will remain will be superb. Things in the future are always great. You can't prove they aren't.
Logs, lore things, even paintjobs and other store cosmetics, like f.ex suits - those things were prepared long time ago, even if they didn't appear in the game straightaway. As a proof - elements of recently added vintage suit, NPC's wore from the start. They waited a year before adding it to the store (which is part of their marketing strategy I suppose).
And CG's? If it's not a generic one - it's nothing special. They've made this game so it needs something like Game Master position to organize an "event" once in a blue moon, using preexisting elements. This game doesn't have seasonal content, like other games you've mentioned, but that's what narrative is for. It's written earlier (probably years of content) and then someone just follows the script.
It really doesn't sound like they're working on any new things - they just slowly add things prepared earlier as per schedule. No new DLC is being worked on and there are probably no plans for that; they declared there will be no fix on planet tilling (that's big indicator that no atmospheric planet DLC, or any other, is coming - they would have said that planet tilling will be fixed along with that in the future, not that they prefer to fix other things and it's not worth their time); consoles are no longer worked on - all that probably means general reduction of staff working on the title.
I mean, they were keeping silent for few months since December last year, working "incredibly hard behind the scenes", etc. and then they were gradually informing us of all those things that got cancelled, then published the "road map", which was just... sad. They've mentioned "Narrative content" in there, because without it there was almost nothing to list. Just look at it. "Update 14: Next major narrative phase ,stability". That's like, nothing. Maintenance.
I fear it's exactly what Frontier wants us (or shareholders, or whomever) to think, to not loose more money - that it's not in "maintenance mode". Because it has "road map" (although I think most of the time during those months when they were "working incredibly hard behind the scenes" were spent trying to decide what else they could add to it except "Optimisation" and "stability" to not look so horribly empty). Who would buy ARX if they knew the game is near the end of it's life? They will keep the game in this limbo state for some time, constantly pretending it's fine - but sadly I don't think there's a bright future ahead. I would love to be wrong, but nothing out there makes me optimistic.