The biggest thing that I see with this is that if Bitcoin attempts to fill this void, it may cause regulations by the government just because they know this is the reason that bitcoin is being used for those people. It's not something that is going to help Bitcoin in the least and I wouldn't want to see it fill this void.
It's not going to help Bitcoin at all and it may see a bit of a surge for a little while in the means of more people using it but it will just make it harder for the rest of the people that want to use Bitcoin for a way that is accepted by the government.
It'll fuck Bitcoin if it fills this void, don't do it and heed the warning.
It is only natural for people to try to find the best way to take advantage of their resources, if you want to buy a car and in a car dealership and the car cost 20k and in another the same car costs 15k then it makes sense to buy the cheaper one, it is that simple.
If people choose bitcoin for this international money transfer, it won't really affect price, because if someone buys bitcoin and transfers it to the family, the family will convert it into fiat as soon as possible, because they need the money in fiat, not in bitcoin. If people in these countries will be able to spend their bitcoins in shops, etc. then it will increase the demand and the price as well. Bitcoin needs to build up more acceptance, that's a key.