Here is a look at the new onsen symbol Japan will begin using:
According to the The Ministry of Economy, Trade and Industry (METI), the symbol could be misinterpreted by foreigners as the mark of a restaurant that serves hot food. To avoid confusion, three people have been added to the onsen symbol, to clarify the fact that the image is used to represent hot spring bathing.
I have never once been confused by the old symbol, although I guess it could be argued this is not aimed at people like me who live in Japan. While there is a bit of nostalgia with the older symbol, the update does make sense when looked at from the perspective of the huge influx of tourism expected in the years up to, and include, the 2020 Olympics.