No, they're saying they would pay for new software. Many ~10 year old cars have all the hardware necessary to support things like CarPlay, but because CarPlay didn't exist yet they do not have it. A lot of people would probably happily pay $200 to add it to their car without having to shoehorn in a third party head unit.

I think it was more about offering features on cars manufactured prior the new feature was released...

Not really. CarPlay didn't exist when the car was made. The car manufacturer had to add software integration even if the hardware was already competent. Parent comment is saying they'd pay to receive this added integration.