Bosch pulled their saws from the US market because SawStop sued and forced them to. Then SawStop started lobbying to have their own design mandated on all saws. It was only later that SawStop said they'd allow Bosch (presumably in order to collect patent license fees).
As to this proposed mandate... If it's mandating any safety device, and Bosch and others can freely compete without everyone paying SawStop, I'm all for it. But if it's mandating the SawStop design, or would require all competitors to pay SawStop, forget it.
You have the order wrong, first they lobbied (2011), then Bosch introduced (2015) and pulled their saws (2017). Then SawStop reached an agreement in 2018. And the reason Bosch hasn't reintroduced it is apparently interference from cell phone signals. https://toolguyd.com/bosch-reaxx-table-saw-why-you-cant-buy-...
As to this proposed mandate... If it's mandating any safety device, and Bosch and others can freely compete without everyone paying SawStop, I'm all for it. But if it's mandating the SawStop design, or would require all competitors to pay SawStop, forget it.