In fact, there are no plans, that have become public (at least I didn’t notice).
But in an interview with the magazine techcrunch Bas van Abel has touched this topic:
When — or even whether — there will be a Fairphone 4 is a question he isn’t keen to engage with. Clearly the hope is Fairphone 3 packs enough smartphone punch to go the distance. Though he hints it might look to offer additional smartphones in order to enter the US, a major market it’s so far not addressed at all.
And I guess, one can not exactly say, that FP is available worldwide, when the phone can be shipped internationally, but technically is not supporting all countries.
Warranty is just one point to take into consideration. You in fact can claim it with the vendor -; though you have to pay shipping and be really patient, if you send the phone around half the world.
Another - maybe even more relevant - point is coming by spare batteries. You can order all other spare parts as well; but batteries will be a problem. Since they are considered dangerous goods, there are shipping restrictions/requirements. As a result resellers do not ship solitary LiIon-batteries worldwide.
I haven’t checked all resellers, so someone might try to do so. Please post any positive results here in this forum. I.e. in the wiki on FP3 resellers
And if remember correctly from a thread of Canadian Fairphoners, shopping and shipping internationally with Clove.co.uk comes cheaper.
(By the way: avocadostore is just a marketplace. Buying there in fact is buying with vireo.)