'Notch' The first thing comes in the mind after hearing the word notch is the iPhone X. iPhone X was released in Sept 2017 and for minimising the bezels Apple put all the sensors, front facing camera, the speaker at the top in a small cut-out and this is how the notch was born. Since the launch of notch people have mixed feeling about them, some like them, some hate them, some of them doesn't care. For those who don't mind the notch will not be affected by the news that smartphones in the near future will have notches, not only Apple devices but also the Android's, but for those who hate the notch, might not be appealed by the news.
Since the bezels on the smartphones are shrinking and getting small there is left behind no place for front facing essentials on the front, things like finger print sensors, front camera, sensors, ear piece etc. The finger print sensor has moved to the back or sides of the phones to house a bigger display, the ear piece and front camera and other sensors are housed in tiny bezels at the top on the notch. Some phones have got rid of the entire top bezel having the front camera and sensors at the chin of the phone and using a piezoelectric speaker for ear piece, where the whole front of the phone vibrates to produce sound (like in xiaomi mi mix). But there is no true bezel-less phone which is at-least 98% screen to body ratio, we can put the front sensors on the top in the frame, we can house the mic in the frame, piezoelectric speaker can be used for earpiece, we can have the finger print scanner on the back or under the display (though this technology is also new and we might not see smartphones using this feature this year but it exists), but the only thing which is the barrier to the full bezel-less display is the front facing camera.We cannot get rid of it because at this point in time people might be fine with no rear camera but they would be mad if there is no front camera.
There is no technology to put the camera under the display (it would be awesome though). Vivo came up with a unique solution with their Apex Concept Phone, where the front camera is at the top embedded in the frame from where it pops out when the camera is being used. But it has to use some motors to do to that, and motors in a smartphone doesn't sound a good idea, its reliability the replacements etc, in addition the problems for water proofing. Its still a concept phone and we don't know if it is ever going to hit the shelves. So in theory there is no place where we can put the camera other than the front, that's why I believe in 2018 more and more phones are going to have notches. The essential phone was the one where it all started and than the big fish Apple decided to adopt the notch and the rest is all notches.
A number of devices that are already released or are going to be released in the future are going to adopt the notch. A few names are LG G7 is rumored to have the notch, the Oneplus 6, Huawei p20, Vivo V9, Oppo F7, Asus Zenfone 5 and many more to come. Google has also accepted the notch and in the developer preview of their new version of android (Android P) they have an option to enable the notch cut-out for the developers to develop their apps around the notch.
Since there is no proper place for the front facing camera at this time, apart from a couple of smartphones, we might prepare ourselves for seeing notches everywhere, because it is the future if you like it or not.