I understand that weak algorithms have been removed. I don't think the problem is the
host key. The problem is the user key.
In a vanilla F33 instance in EC2, you have no way to connect to it. The EC2 creation
process uses cloud-init (I think) to inject a user key into the default user's
~/.ssh/authorized_keys file on first boot. The EC2 process will only inject an RSA key.
The SSH daemon on F33 won't accept any RSA keys. Thus, you can't connect.
And since there's no back door, no console, there's no way to get to the instance,
at least that I can figure out.
In other words, I can't figure out how anyone can use an of the "Fedora 33 Cloud
Base Images for Amazon Public Cloud" listed on:
https://alt.fedoraproject.org/cloud/
I'm not sure how one can connect to an image after creating it.