That's not entirely true. Rooting Kitkat in itself will not prevent OTA. If op made any system partition changes, it "may" prevent the OTA update from installing successfully.
@Not Lykeli - after rooting, have you made any changes to the system partition? (besides installing TWRP recovery, and the superSU, what else have you done (besides installing apps from the play store)? Have you deleted/edited any system files? Have you installed XPosed framework (or other root apps)?
If you have not made any system partition changes, you should be able to download the OTA file from google, and store it on your phone, and reboot into your TWRP recovery, and flash it from there.
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