The Flight Review is a requirement IF you need the FAA license to fly. That said, if you are flying in the country where another license was issued by that country, you don't need the FR because you don't need the FAA license. If you couldn't fly an N-reg without the FAA license, you need the FR for sure.
Most don't get them, I have even offered to do the FR for free, when pilots actually needed them, and they didn't want to do it. The reasoning is that the FAA isn't going to show up on the ramp.