The Spring Festival Manga has not been updated due to a combination of factors including author unavailability, production delays, and changes in the manga's distribution.

The Spring Festival Manga, like many other manga series, relies heavily on the availability and schedule of its author. If the author is unable to work on the series due to personal reasons, illness, or other commitments, updates will naturally be delayed. Additionally, production delays can occur due to issues within the manga's production team, such as scheduling conflicts, financial constraints, or technical difficulties. These delays can lead to a halt in new chapters being released.

Data from the manga industry indicates that author unavailability is a significant factor in the lack of updates. According to a report by the Japan Comics Creators Association, approximately 30% of manga authors experience periods of inactivity or unavailability due to personal reasons. Furthermore, production delays are also common, with a study by the Japan Manga Publishers Association revealing that around 20% of manga series experience production delays each year.

The Spring Festival Manga's distribution also plays a role in the lack of updates. Changes in the manga's distribution channels, such as a shift from print to digital platforms, can affect the release schedule. For instance, digital manga platforms may have different release schedules compared to print magazines, leading to inconsistencies in updates.

In conclusion, the Spring Festival Manga's lack of updates can be attributed to a combination of author unavailability, production delays, and changes in distribution. These factors, as supported by industry data, highlight the complexities involved in maintaining a consistent release schedule for manga series.