Yup, that's exactly what I did last night (didn't post about it as it was too late)! Except I updated to 10.0.14 manually (OTA updates weren't triggering). Found the ROM somewhere on XDA (the official ROM on OnePlus' website was 10.0.15 and I really want OTA updates to work -- so holding out for that. I'm guessing OTA didn't work from 10.0.8 as it's too far back?)
In any case -- installed 10.0.14 manually, rebooted into the phone, factory reset it, rebooted again, and turned off at the start/setup screen. Restarted in fastboot mode, ran
fastboot oem lock, used the volume key to select "lock my bootloader" and hit the power button to select -- the phone restarted, wiped again, and finally rebooted into the phone setup screen! So yes, it seems that if you flash an official ROM, factory reset, and finally lock bootloader, it's able to go through without corruption.
dont usually comment on stuff but i finally got everything working (make sure drivers/etc all updated) so hopefully this is helpful wrt OTA updates:
Last night when flashing my phone, I extracted the global ROM and used the ADB platform tools that came with the ROM. After getting my phone working, the system update feature would say my phone would say it was up to date despite running an old version (ex: it would say 10.0.8 as version and that phone was up to date). This morning when I extracted an older rom (10.0.8) in to the most recent platform tools folder (without replacing/copying over pre-existing files) and then flashed it, my phone said it was eligible for an immediate update.