Because now, the authorities must be carefully analyzing every detail of these records and checking all onchain movements, as well as comparing them with addresses that they have referenced as suspicious. This will involve long hours (days/weeks) of analysis, which will certainly lead to some time without news about this process.
They probably have some sort of software where everything gets analysed after various data is inputted. Receiving outputs really should not take too long.
At this point, it's no longer worth getting desperate. I believe that for the majority of users, it will not be something to worry about, because the authorities will be focused on big criminals who already know that they use Bitcoin as a way to finance their schemes.
I would like to think those that used Chipmixer or other mixers for privacy reasons on extremely small scales such as when receiving signature campaign fees or when asking for micro loans in the forum, would most probably have nothing to worry about.
However, by far the majority of those that used Chipmixer for nefarious purposes will be concerned because if any transaction via Chipmixer can be linked directly to them they will end up facing serious criminal charges. The accusation of $3 billion laundered is very serious therefore those that used Chipmixer for money laundering and other crimes could now be worried about being arrested, having possible criminal investigations against them and could possibly also have their personal assets seized.