From a little research on why grand jury testimony is secret...it is about these 3 things.
(1) preserving the willingness and candor of witnesses called before the grand jury...
(2) not alerting the target of an investigation who might otherwise flee or interfere with the grand jury.. and
(3) preserving the rights of a suspect who might later be exonerated.
So there can be a heck of a lot going on with #2 and #3 on that list especially as Barr has opened up new investigations into FISA malfeasance.
I wouldn't expect that testimony to be released from any judge while investigations are proceeding.