If you're wondering that OnePlus is launching a new handset then you must know that OnePlus itself is calling it an enhanced iteration of the existing OnePlus 5 flagship phone. Judging it as a new phone will be unfair so we'll be looking at the OnePlus 5T as an update to the OnePlus 5.
In markets like UK and US, the phone isn't just an upgrade though – it’s also a replacement, as OnePlus has ceased production and sales of the phone it launched just six months prior to the arrival of the OnePlus 5T. But in India, the company has no plans to discontinue the OnePlus 5 as of now, so there are high chances that OnePlus will go for a price cut on the previous iteration model.