As the short-haul 767s are not etops certified, any Long haul 767 route that doesn't involve flying the Atlantic is a candidate for substitution.

Cairo, Moscow and Saudi have been the usual victims...

If you know it is a sub. and you are not happy, then complain or change to a different routing.

Whilst things breakdown, there is a balance between working the fleet so hard that there isn't any slack and having an equivalent back-up.