Earlier in the week, Samsung, during the launch of the Galaxy Tab S3 and Galaxy Book, officially announced that the company will host the Galaxy Unpacked 2017 event on March 29, which presumably meant the long rumoured Galaxy S8 will finally break covers this month-end. Now, the new information has emerged revealing when exactly the Galaxy S7 series successor will hit stores.

After unveiling the Galaxy S8 series at two locations—New York City and London—simultaneously on March 29, Samsung is expected to commence the pre-order service on April 10 and finally release the product on April 21, reported The Investor, citing company insider.

We believe this might be a real deal, as most recent rumours have indicated the same.
Even the release pattern is same. Though, the launch date is a month late compared to last couple of years, the time-gap between the unveiling and the market release date is same.
Samsung Galaxy S8: What we know so far:

As per recent reports, the Galaxy S7 series is expected to come in two variants— 5.8-inch Galaxy S8 and 6.2-inch Galaxy S8 Plus.
As far as design language is concerned, both the models will have dual-edge curved screen sans physical home-cum-fingerprint scanner button. Leaked images have suggested that the biometric sensor is re-located to the back-side, just right beside the camera module.
Under the hood, the phones are said to house 4GB RAM, 64GB inbuilt storage, 12MP dual Pixel camera, 8MP front snapper integrated with IR emitter to act as Iris scanner, Android Nougat and AI-based Bixby digital assistant.

Word on the street is Samsung Galaxy S8 and the S8 Plus will come in two sub-variants. America and other developed markets-bound model will house Qualcomm’s latest Snapdragon 835, whereas emerging markets like India, will get Exynos 9 series 8895 processor.