If you own an Exynos Galaxy S8 or Galaxy S8+, then you’ve been able to flash an official TWRP recovery image since the last week of April. These international Galaxy S8 variants are far easier to unlock than their Snapdragon counterparts, as all you simply have to do is go into the Developer Options menu to enable the OEM Unlock option. Snapdragon variants are more locked down and while most Snapdragon Galaxy S8 and Galaxy S8+ models have yet to receive an official bootloader unlock method, official TWRP recovery images have already been ported for them.
This is possible thanks to the maintainer, XDA Recognized Developer / Contributor jesec, who is actually the same person who put together the TWRP images for the international Galaxy S8/S8+. The current version for this release is 3.1.1 and they’re sure to warn users that these specific images will in no way work on the Exynos variants of the Galaxy S8/S8+. This includes, but not limited to, the International (F/FD), Korean (N), and Exynos LDU (X) variants.
As you are likely already aware, most versions of the Snapdragon S8 and S8+ come with a locked bootloader, but that isn’t always the case. Samsung has opted to ship the Snapdragon S8 and S8+ in countries like China and they don’t seem to be locking down the bootloader there. So while these TWRP images are available for those current versions with an unlockable bootloader, the recovery will be far more relevant once other Snapdragon models receive official bootloader unlocking methods.