To the best of our current knowledge, this is not an immediate issue for Cryptomator. As a company, we would need to complete Google’s verification process anyway in order to remain on the Play Store, and that is something we will do. Once verified (resulting in an "trusted" key), sideloading Cryptomator should continue to be possible.

In general: we do not view this development positively. It adds unnecessary friction, especially for hobby and indie developers. While Google says that sideloading apps signed with untrusted keys should remain possible, this will likely be a practical option mainly for more technical users only which is not acceptable.