When you head to settings SIM Status Menu in your phone, you will notice that your current version gives you access to view network signal strength information but future Android version may give carriers access to the feature and they can decide to disable it for users.
Some reports says the feature was requested by carriers and Google agreed to their demands. Meanwhile, the reason why they had to request for the feature wasn’t revealed.
However, the change will only affect the signal strength but not the API used in fetching the information. This means that you can still use third party apps to show signal strength.