My understanding (getting this all entirely from Michael Geist, who's been remarkably consistent advocating for an open internet for years now) is that the government's ability to set regulations for this bill are quite limited.

Now that the bill is passed and could take effect at any time, and that there really isn't much the government can offer in negotiations at this point, is that Meta is just moving on and putting all this behind them. From an implementation standpoint, Meta also needs time to make sure that their news blocking is done correctly as any bugs in that process after the law takes effect could be extremely costly.

Plus, the government and supporters of the bill are slowly being forced to realize that Meta wasn't lying when they said that they could live without news content. Engaging in a negotiation process, especially one that won't deliver what Meta wants, will only delay when the bill's supporters eventually recognize that the assumptions underpinning this bill (that Meta is stealing value from news organizations) were false.