Judge Stephanos Bibas granted the parties’ request to allow briefing on whether the court should conduct a filtration hearing to determine if some elements of West’s works are not copyrightable as a matter of law. The defendant ROSS Intelligence supports a filtration hearing, but Thomson Reuters, the plaintiff, opposes it.
The briefing schedule is:

Entertaining the parties’ arguments over a proposed filtration hearing seems reasonable. We will have to wait for ROSS’s arguments. If the briefing establishes colorable examples of uncopyrightable elements of the plaintiff’s works, then a filtration hearing may well be warranted.
The courts’ “distinguish[ing] between the protected and unprotected material in a plaintiff’s work,” in what the 9th Circuit calls the extrinsic test of infringement, requires the court to undertake a gatekeeping role. My co-author Andrew Moshirnia and I discussed this gatekeeping function in music infringement cases in a law review article (see pp. 723-24). Granted, Delaware is not in the 9th Circuit, but copyright infringement must still be based on copyrightable expression. In other words, copying unprotected elements is not infringement, no matter the circuit.
And, even if a filtration hearing is held pre-trial, the court could always decline to make a ruling of uncopyrightability or defer it.