Because holding someone in pretrial confinement has nothing to do with having "enough evidence to hold them there." It requires:
- A reasonable belief that a crime has been committed, AND
- A reasonable belief that the accused committed the crime, AND
- That in the absence of confinement, the accused will commit more crimes or is a flight risk, AND
- That lesser means of restraint won't prevent 3.
If they're no longer deemed a flight risk, or one of the multiple reviewing authorities of the pretrial confinement says "no, I don't agree, you didn't prove 1-4 to my satisfaction," the accused is released before trial. This is a state that can change. Someone can be a flight risk and then change their mind. Or, they can get put on pre-trial restriction, violate it, and then get thrown in the clink.
Look at the warrant. Look at the first page of the warrant. Look at the very top line of the first page of the warrant. Look at literally the first thing you see. It was filed under seal 11 months ago.