At the time, Samsung has only two foldable phone models. With each successive generation, the Galaxy Z Flip and Z Fold become more popular, and a recent report from Galaxy Club claims that a third foldable could be released this year.
This is because new codenames B4, Q4, and N4 have been seen in the wild, according to the tipsters. The N4 codename could only be a new foldable phone, as B3 and Q3 belonged to the Galaxy Z Fold 3 and Z Flip 3 last year. In contrast to the Z Flip and Z Fold handsets, Samsung does not plan to make huge quantities of this phone, according to the report. It's possible that Samsung wants to see how well the N4 is accepted in the market before ramping up manufacturing on a massive scale.
Samsung has already released a number of patents demonstrating both rollable and foldable phone designs. Given the limited manufacturing, the N4 might just have a unique design, but that's just speculation for now.
Samsung normally announces new foldable phones in the middle of the year, so we can expect an official announcement then. Stay tuned until then.