Sony did not announce a new APS-C camera at the 2018 Photokina show and it seems they will not announce one this year. The Japanese website pronews.jp recently interviewed Kenji Tanaka (Sony Senior General Manager) who confirmed that Sony will announce a new APS-C based mirrorless camera by the CP+ show that will take place in Japan at the end of February (February 28th - March 3th). He also emphasized that Sony has not abandoned their APS-C mirrorless camera line.
The last Sony a6500 APS-C mirrorless camera was announced in October 2016. The Sony a6300 was announced in February 2016. The model before that (Sony a5100) was announced in August 2014 (the Sony a6000 was introduced in February 2014).
Via SonyAddict