JR Central has formally announced that it will build new commuter trains to replace older ones from the 80s, 352 cars of the new 315 Series EMU will be built from 2021 to 2025 to replace the 211 (250 cars), 213 (28 cars) and 311 (60 cars) series and it will cost 72 Billion Yen
https://jr-central.co.jp/news/release/_pdf/000040199.pdf*This bit was actually revealed from an interview with the CEO of JR Central a few weeks ago but is now "official"
>>1441093It is probably due to the Capital Area is covered up to Iwaki Station right now so extending up a bit makes sense