What is keeping them from filing, at the last minute, just anticipating her announcing? I don't buy this theory at all.
The July 26th cut-off date doesn’t preclude last minute nuisance filings but it does let her legal staff know the approximate costs of her defense and the amount of time she might have to devote to her defense. A short while back her lawyers succeeded in move on case to a federal court (IIRC).
Shutting the door allows her to plan for the future knowing she won’t get bush-whacked later. Sound business plan.