That your camera can save files in Adobe RGB is only of any importance for the in-camera generated JPEG. RAW files from your camera have no colour space as such, the data in RAW files is a record of what the camera sensor captured.
It’s only when the RAW data is read by PL / [insert name of any RAW processing software] that the sensor data is mapped into a colour space. If during that mapping process PL / [insert name of any RAW processing software] encounters RAW data that corresponds to a colour that is outside the colour space into which it is mapping the RAW data then a decision has to made as to how best to fit that out-of-gamut colour into the working colour-space.
By using PL’s Wide Gamut working colour space it is less likely that the mapping of the RAW data into a colour space will encounter out-of-gamut colours compared to mapping the RAW data into PL’s legacy working colour space. Thus using PL’s Wide Gamut working space ‘preserves’ more of the colours captured by the camera sensor.
Being able to see the colours that result from the RAW to working colour space mapping process is another matter. Regardless you how wide the gamut of the working colour space you will only be able to see the colours that are within the gamut of your monitor or your printer. Meaning once again a decision has to be made about how to best present colours that your monitor or printer can’t display within the gamut they can show. That decision is otherwise known as colour management and involves calibrating and profiling your monitor (and ideally your printer as well) and ensuring that these devices use the ICC profiles that are obtain by the calibration an profiling process.
Purists here will take me to task for over simplifying the above process but I think it’s near enough to at least get people started on their understanding of what can be a confusing subject.