In addition to Gosho’s personal message, Shogakukan reports that Gosho already went in and out of hospital repeatedly last year, but decline to specify his illness for privacy reasons.
After File 920, which will be published in this week’s issue (SS #16), there will be no new file in issue #17. It is still unclear whether there will be a new file the following week (#18). Starting from issue #19, Shounen Sunday will run reprints of old Detective Conan files. When and how often new files will be published during Gosho’s hospital stay is still unclear.
Source: Yahoo Headlines