As Powerline notes, Mueller probably didn't see that coming - and the indictment itself was perhaps nothing more than a PR stunt to bolster the Russian interference narrative.
I don’t think anyone (including Mueller) anticipated that any of the defendants would appear in court to defend against the charges. Rather, the Mueller prosecutors seem to have obtained the indictment to serve a public relations purpose, laying out the case for interference as understood by the government and lending a veneer of respectability to the Mueller Switch Project.
One of the Russian corporate defendants nevertheless hired counsel to contest the charges. In April two Washington-area attorneys — Eric Dubelier and Kate Seikaly of the Reed Smith firm — filed appearances in court on behalf of Concord Management and Consulting. Josh Gerstein covered that turn of events for Politico here. - Powerline Blog
Politico's Gerstein notes that by defending against the charges, “Concord could force prosecutors to turn over discovery about how the case was assembled as well as evidence that might undermine the prosecution’s theories.”
In a mad scramble to put the brakes on the case, Mueller's team tried to delay the trial - saying that Concord never formally accepted the court summons related to the case, wrapping themselves in a "cloud of confusion" as Powerline puts it. “Until the Court has an opportunity to determine if Concord was properly served, it would be inadvisable to conduct an initial appearance and arraignment at which important rights will be communicated and a plea entertained.”
The Judge, Dabney Friedrich - a Trump appointee, didn't buy it - denying Mueller a delay in the high-profile trial.
The Russians hit back - filing a response to let the court know that “[Concord] voluntarily appeared through counsel as provided for in [the Federal Rules of Criminal Procedure], and further intends to enter a plea of not guilty. [Concord] has not sought a limited appearance nor has it moved to quash the summons. As such, the briefing sought by the Special Counsel’s motion is pettifoggery.”
And the Judge agreed...
A federal judge has rejected special counsel Robert Mueller’s request to delay the first court hearing in a criminal case charging three Russian companies and 13 Russian citizens with using social media and other means to foment strife among Americans in advance of the 2016 U.S. presidential election.
In a brief order Saturday evening, U.S. District Court Judge Dabney Friedrich offered no explanation for her decision to deny a request prosecutors made Friday to put off the scheduled Wednesday arraignment for Concord Management and Consulting, one of the three firms charged in the case. -Politico
In other words, Mueller was denied the opportunity to kick the can down the road, forcing him to produce the requested evidence or withdraw the indictment, potentially jeopardizing the PR aspect of the entire "Trump collusion" probe.
And now Mueller is pointing to Russian "interference operations" in a last-ditch effort.https://archive.fo/54FqYhttps://www.zerohedge.com/news/2018-06-12/mueller-scrambles-limit-evidence-after-indicted-russians-actually-show-court