A fresh rumor regarding the anticipated 2020 iPad Air fourth-generation model suggest that Apple will indeed go ahead with increasing the display size of the device from 10.5-inches to 11-inches. This gels with a previous rumor although the latest rumor also suggests that Apple will also move the next iPad Air from a Lightning connector to a standard USB-C port.
https://www.notebookcheck.net/iPad-Air-fourth-gen-to-get-display-increase-to-11-inches-Apple-A13-Bionic-SoC.467714.0.html