I wouldn't place too much hope in Paizo launching a big fight back.
Here's how I see things: WotC's big goal at the moment isn't about money per se (the OGL is small fry) - the main thing they want is to end Open Gaming as a concept. That means getting people to stop using the OGL 1.0 and, ideally, avoiding a challenge in the courts. They know that Paizo are the company best placed to launch that challenge, and also the ones with the most to lose.
Meanwhile for Paizo this is an existential threat - their existing games are too bound to the OGL to carry on as they are, and a court case would be at best highly expensive and very risky.
If I were WotC, therefore, I would offer Paizo a license to continue using anything and everything in the 3e and 5e versions of the SRD, royalty and reporting free, for X years - long enough for them to see out the current editions of Starfinder and Pathfinder. In return, they'd sign away their ability to use the OGL, and the new editions when they come would need to be new enough to avoid the need for an ongoing license.
And that way they both get what they want: Paizo carry on without legal headaches or risks, and WotC nullify their biggest risk. (It also explains their radio silence - negotiations are likely ongoing at how many years they need.)
And if that is the case, I absolutely couldn't fault Paizo for taking the deal. As I said, it's an existential threat, and they have too many people depending on them not to at least consider it strongly.