No, devices no longer need to require the special chip to work with Homekit. According to Apple -
"We're also making one other big change to simplify development: we're no longer requiring that every HomeKit device contain a specific security chip. Instead, we'll allow companies to authenticate their devices entirely using software. Smart home devices out on the market that don’t already support HomeKit will even be able to use this method to add HomeKit support after iOS 11 launches this fall."
So basically everything can be handled by software updates.