I installed the OTA via TWRP RC2 for 7.1.2 e version and upgraded from e to k again with OTA via TRWP RC2. I did this for both the Pixel and the Pixel XL. Not only have I had no issues, but the update ran very fast, I used the RC1 temp img and then did the full RC2 install each time as well as rooting with SR3-SuperSU-v2.79-SR3-20170114223742. Only (known) issue was having to use the December ADB/Fastboot Google files and not the March ones.