Who or what decides how profiles are applied (or supplied) for Lightroom? (I'm using LR CC 2015.12 on my Mac.) I have a Canon EOS 6D and if I import JPEGs there is a long list of available lens profiles. On the other hand my Canon EOS M6, though supported by LR, only has RAW profiles. Why so? And why are JPEG and RAW profiles different if they are largely to correct lens aberrations?
In camera developed jpg can not be guaranteed to be identical to RAW for applying a profile.
That is why a profile is generated for either jpg or RAW.
You can copy a RAW profile and change it so it an be used with a jpg. However, your mileage may vary depending on the lens and camera.