Reducing stress can certainly reduce the symptoms of BP. That doesn't mean the diagnosis was incorrect, only that the disorder has gone into remission. It could recur, either randomly or due to unavoidable life issues adding stress again.

It's never a good idea to go off your meds unsupervised. A good doctor will listen to you when you tell them your life stresses have reduced and help you reduce meds safely while monitoring you for returning symptoms.

Even if you're fine off meds now, you'll still have BP and have to be aware of the possibility of symptoms returning and needing meds again at some point in the future.