Personally I think the expansions are still in early production.
It really depends, there's so many factors you have to take into account.
1) Are we staying in NC or close to it? (If not that's a whole entire new map), I'm not sure when dialogue is written in the development process. I would imagine they have to have an idea of where something will take place for dialogue to make sense at times. I would say same goes for motion capture. Once again I'm not a developer in anyway so I'm not sure how the development process works.
2) Dialogue (How much do they have to record and who do they have to record?) This is important because if its mid game story content, its in all likelihood Keanu Reeves recorded lines already (Thus meaning its likely well into development).
3) Does the expansion relate to the main story in anyway or is it a completely separate/new story?
4) Did they know this game was going to have as bad of a release as it did way before being released? This is important because if they've known this, its possible that expansions were put on the backburner for a while now.
5) Are we going to be getting larger size free DLC? This in all likelihood won't be the case, but if we do get a lot of "larger" size content in the form of free DLC, it could have taken time away from expansion. I think this is very unlikely for many reasons which I'm sure many of you can think of.
6) The first expansion is already done and they are pushing it back for various reasons.
7) Maybe they want to wait till more people have next-gen consoles, so that many more people upgrade to the next generation version. Biggest reason for this being so that they can say that previous generation consoles won't be getting these expansions for hardware reasons. Its easier for them to wait until late 2021/early 2022 when its likely significantly more people will finally get access to next gen consoles, meaning less criticism because everybody will have a stable version of the game by then.
There are many more reasons that can be said, but hopefully I made my point. There are so many factors that could point to the expansions not even being started yet, mid way throught development, or even possibly even finished. It's really hard to say because we don't know how much was actually cut, we don't know how many hours these DLC are intended to add, we don't know how different it is from the main game/story, we don't know how severe the release was manipulated by the base games release, we don't know the direction of free DLC yet, ect.... So yeah, a lot of different factors.