I don't see why they wouldn't wait until the ruling on a preliminary injunction.
DD will have his view - here is mine.
You never know how a judge will rule in complex matters until he does. And the time to cut a settlement is while both parties recognize the RISK.
By granting the TRO the judge has put Amphastar/WPI at risk. IF they ever considered a settlement, now is the time to do it. This fact setting also argues strongly for courts upholding a settlement if struck, as not being in restraint of trade. Delaying a competitor certainly does not look like restraint of trade if there is a significant possibility of a PI, as must now be evident to all.
Some judges will even make rulings to induce settlement and then reverse themselves to create an atmosphere of uncertainty to pressure the parties to settle.
Over confidence is a novice error in litigation. I know - I have made it with serious consequences. Settlements that split the rewards leaves both sides reasonably happy.
ij
It is astonishing what foolish things one can temporarily believe if one thinks too long alone ... where it is often impossible to bring one's ideas to a conclusive test either formal or experimental. J.M. Keynes