When printing the public key from a private key-file, using the flag -y of ssh-keygen, there is no way to print that key's comment, although in the new OpenSSH private key storage format the comment is saved inside the private key. One possibility would be to print it when optionally adding the -v flag to the -y flag.
Created attachment 3315 [details] print key comment when printing pubkey from private
this has been committed and will be in the OpenSSH 8.1 release soon.
closing resolved bugs as of 8.6p1 release