The Exynos 9285 has been proven inferior to the Qualcomm Snapdragon 855, so is it any surprise that Samsung is switching to the Snapdragon 865 for the Galaxy S11 series? Europeans are still set to receive the lesser Exynos version though, according to multiple sources.
https://www.notebookcheck.net/Reports-claim-that-Samsung-has-dropped-Exynos-in-all-but-one-region-for-the-Galaxy-S11-and-Galaxy-S11.447131.0.html