Yea it’s because your car will be fitted with a petrol particulate filter. Not sure if it would throw errors if removed or that as I haven’t seen what sensors are fitted to it.
I had the option of a 2018 jcw or the challenge 210 I ended up with the 210 because it had so many options and that exhaust.

Hopefully you can fit one with no major issues as it’s fantastic for a blast