It's checking for certificate status, not so much phoning home. To my knowledge, it is only sending some hashes to Apple. It is not sending any personal data.

Here is a good write-up on the issue:

https://www.sentinelone.com/blog/what-happened-to-my-mac-app...

I recommend that people not block oscp.apple.com as it has security benefits. If your threat model dictates blocking oscp.apple.com then you probably should not even be running macOS (or Windows).