Funny how we take something and draw a straight line from there to the moon without really taking into consideration tail events and peripheral factors.
Rwanda has one of the highest birth rates in the region and I expect that the population is growing really fast as well. Also, Rwanda is starting from a very small base - the country was already doing rather poorly back in 1994 when the genocide happened. A lot of the development that has taken place in the last almost 20 years has been playing catch up after their GDP was halved.
If the US has not eradicated poverty in over 200 years and even tiny little postage stamp Cyprus with its proximity to Russia is doing so badly, I would put on chips on Rwanda eradicating poverty.... Besides, poverty gets redefined with every passing generation.
Rwanda is such a tiny country that methinks it is possible to do this in under 10 years with all the international goodwill the currently enjoy! In fact just a 'stool sample' from handful of the globabal billionaiares who have joined the giving pledge is enough to eradicate poverty in Rwanda!