Usually, Galaxy S series devices are launched in Feb-April. According to the news report in The Bell, Galaxy S9 will release earlier than usual. This will happen because the primary component, the OLED panel, required for phone’s assembly will reach Samsung in November.
Check out: Best Android O features
After display panels reach Samsung, it takes about 2-3 months for phone’s entire assembly. To recall, Galaxy S8 display panel shipment started in January 2017 before its official launch in March.
Based on traditional time periods, if display panels reach Samsung in November, the S9 will likely debut in January.
Further, recent rumors suggest that S9 will feature a modular design similar to Motorola Moto Z series. If S9 comes with mods, users can attach accessories externally to the device *fingers crossed*.
Source: The Investor