It’s pretty common for corporate stuff (legal or otherwise) to start with no payment changing hands, just a contract. Then an invoice lands either monthly or on completion afterwards.
That makes it easier for the work to actually start (otherwise you need to engage the finance dept up front and they’re often slow), and once the contract is signed and the work started that’s the sales process complete.
Guaranteed they’d find a way to double dip. Price gouging, restricting content behind further paywalls, adding ads anyway… absolutely they’ve investigated all those and undoubtedly more.
Switch to Firefox, Chrome is their biggest lever to force this kind of stuff onto people. While Firefox exists and it remains uncool for them to block it they’ll have to compete against piracy and adblockers which will limit their ability to aggressively monetise.
Switch to firefox!