The authorized_keys file will not change. ssh-rsa as a key format will stay (it isn't specific to sha1 or sha2), just the client and server need to upgrade to

The authorized_keys file will not change. ssh-rsa as a key format will stay (it isn't specific to sha1 or sha2), just the client and server need to upgrade to sign/verify session-specific signatures using sha256 instead of sha1. rsasign(sha1(sessiondata)) becomes rsasign(sha256(sessiondata)). OpenSSH CA certificates are more urgent to upgrade since those are/were long lived sha1 signatures - sha1 there got disabled a couple of releases ago I think. The article seems bit sensational and lacking understanding.