It's fixed and wired to the house, therefore it stays with the house unless you've specifically stated that you're taking it. By the logic that its not mentioned at all, means you can take it with you is rubbish. Have you mentioned every electrical socket inside the house in the documents ? Does that mean you can remove and take all the sockets in the house with you ? Of course not.
As to whether they would pursue legal action, is that really the benchmark, of whether you should do something ?
As for the ring/CCTV, stickily speaking, I don't think you are supposed to take things that are fixed to the house, which these are. More of a grey area, since they are not wired in. (unless the ring is). If taking the ring leaves the house without a doorbell, and a gap where one should be, I would suggest that you need to leave a doorbell of some description at least, but perhaps that's taking things too far ?
As always, not a lawyer, consult with them.
You can give us the correct info, once you've consulted the correct people.
Edit: Found the below, not from the UK, but imagine rules would be not dissimilar.
The home your clients just saw had all the latest smart home devices. Do they stay with the property when they buy it?As with all good legal answers - it…
cciaor.com
"Many smart home devices, such as an Amazon Echo, simply plug into the wall – or are entirely cordless – making them easily moveable. These types of devices are likely to be considered personal property of the seller.
Other smart devices, such as smart switches, smart thermostats, smart doorbells, and security cameras, may be hardwired, which would firmly place them into the “fixtures” category"