What is the meaning of data symbols when using CAD

Hello Experts,

Recently, I was preparing to use the CAD feature, but I am a bit confuse when reading the SX1261/2 datasheet, as below:

On the SX1261/2, the channel activity detection mode is designed to detect the presence of a LoRa® preamble or data symbols while the previous generations of products were only able to detect LoRa® preamble symbols

what does mean for data symbols? to expaln more clear, let me give you an example, that is

if the symbols I need to detect is 16 symbols, but the preamble length I configured is 8 symbols

in my understanding, CAD IRQ will be triggered when SX1261/2 detected the symbols until it reaches to 16 bytes, not matter if it preamble or the symbols of other fields. correct?

any updates about it?