No, chromium-mir-kiosk is unmaintained and unsupported.
We never supported chromium-mir-kiosk, it is a proof of concept and an experiment. It’s experimental status was reflected by the channels it was published in (edge and beta… never stable)
It has been unlisted from the store for some time and we recommend transition to wpe-webkit-mir-kiosk, maintained by the community.
It can still be installed, because people are using it. But this is on an “as is” basis.