Sure, #LetsEncrypt, you can say that using certificate based client auth is a minor use case and that this functionality was never guaranteed to always be available and all of that. But the fact stays: you are removing a feature from your certificates that has been here for a very long time, just because Google demands this. Why Google wants this? I will ask them. But I am quite sure that this #oopsie side effect is not an oversight.
3/5