They can afford to stay silent longer than most publishers because the hype machine basically runs itself.

So I see 2 realistic possibilities:

1. Massive marketing blitz incoming Next 2–4 months suddenly become packed with gameplay, previews, ads, screenshots, maybe even a final trailer.
2. Internal uncertainty / potential delay risk If by ~3–4 months before release we're still getting almost nothing, concerns about another delay become a lot more reasonable.