The policy of companies, many of which operate in multiple different states, has no bearing on the legality of a citizen recording a conversation.
Because again. That's what this is about, since you erroneously claimed that it was illegal for a citizen to record a conversation without informing the other party.
You've provided multiple links that explicitly and repeatedly say it is legal, in single party consent jurisdiction, for one party to record a conversation without informing the other parties of the recording
Your own sources say this.