I have the opposite situation as this question. I received a call which Google marked as Suspected Spam Caller, but it was a legitimate call from a company I do business with. Can I report to Google that this is not spam so others are not confused? I selected the call in my history, and there is an option to report as spam, but not an option to report as not spam.
You missed seeing this Report a mistake in spam protection
If a call from someone you know is marked as spam, you can report the mistake.
Open your device's Phone app phone.
Tap Recent calls Recents.
Tap the call mistakenly labeled spam.
Tap Not spam.
Future calls from this number won't be marked as spam.