It shouldn't if you router is configured to not toggle the interface down
or you are using the loop-back as update source thing. I don't know for
sure if 50ms is enough to cause the interface to detect it being down or
not. I suspect it depends a lot on the interface.
If you send keepalives every 40 seconds, you will not lose the
interface for a 50ms drop.
You will incur errors, but you will continue to forward packets.
A few will be lost, many will survive.