Not convinced this is particularly accurate statement.
I'm pretty sure most the things I've seen around registration, the majority seem to all be using approx 250g (maybe 300g max) as the minimum weight limit - so an unmodified anafi would need registration.
As you say though, the user needs to check the regulations for where they intend to fly to be sure.
It seems that, when i would like to fly class 2 (45m high) i need to register my drone in Belgium. Other country's have other rules. Only in Belgium there are very strong regulations