Alegeus, a client of DigiCert, filed a court motion to stop DigiCert from revoking their certificate. The courts granted the temporary restraining order.
There is no "update their legal work to prevent customers from legal action" that can avoid a temporary restraining order that is ordered by the courts to provide time to establish facts. Its simply how the legal process works. "they can't help but" seems unfair as the issue was the client Alegeus was unable to replace their certificates in the revocation timeline.
Further "Going through the courts", they didn't go to the courts a client of theirs did.
Digicert is absolutely not blameless. Outside of the TRO, they have failed to meet revocation windows before and yes, are likely using the TRO in this instance as a shield for that.
However the TRO itself is a concerning development that all CA's need to consider depending on their legal jurisdiction, as it could put companies in a bind of being legally ordered to not to complete something they are contractually and legally required to do within the required timeline and interrupt standard security practices in cases like this.