The dialect of Afrikaans as developed by the Boers has not been in official use since the early part of the 20th cent due to the fact that it was removed from the public sphere around 1921 including from the Parliament. Theuns Cloete of Boerevolk Radio noted this during an interview with The Right Perspective shortwave / internet radio program in December of 2007. Historians have classified the dialect spoken by the Boers as Eastern Border Afrikaans which was named after the eastern Cape region where the Boers & this dialect of Afrikaans developed. It is also interesting to note that the Boers did not give the name Afrikaans to the general / macro lingua franca language of the general southern western African region as the term Afrikaans was originally given to this language [ of which there are numerous dialects & spoken by numerous groups ] by the Cape Dutch intellectuals [ who started the propagation of the term Afrikaner stemming from the laguage ] of 1875 who started a language rights movement in order to get the language official recognition as a distinct language at a time when most of the Boers were independent in their internationally recognized Boer Republics & only ever referred to their Afrikaans dialect as "die taal" [ the language ] or Boeretaal.
This further demonstrates a difference in dialect with that as spoken by the Cape Dutch of the Western Cape.
This article from the Times on the Boer Diaspora living in Argentina - who have been there since 1903 descendets of Bitterenders who did not want to live under British domination - notes that the Boers there speak an "older form of Afrikaans" when in fact the correct interpretation is that they speak the unadulterated Boer version as their language was unaffected by the political changes taking place in the then new macro State of South Africa which was inherited by the more numerous Cape Dutch & the consequent predominance of their Afrikaans dialect.
Westerners often have a one dimensional view of Afrikaans & often even view it as a colonial export when in fact the language is a homegrown product of many diverse influences which took shape entirely on African soil when the various people brought there by the VOC from Europe & Asia [ who were brought as slaves ] developed a lingua franca out of necessity in order to communicate among themselves. While Afrikaans did develop from the High Dutch dialect [ not form Netherlands Dutch ] spoken by the Germanic peoples of northern Europe [ mainly in modern day Germany & Denmark ] who were sent to the Cape as servants of the VOC: strong influences from Malay / Portuguese / French / German & Khoi have shaped it into a distinct language of its own with a number of various dialects some of which have died out. There are 3 main dialects of Afrikaans. West Cape Afrikaans spoken in the Western Cape / Northern Cape Afrikaans - of which Orange River Afrikaans is a part of - spoken by the Griquas & the remaining Khoisan people / Eastern Cape Afrikaans spoken by the Boers of the eastern Cape frontier & their descendents. The Boer dialect of Afrikaans has not quite disappeared but was overshadowed by the Cape Dutch originated dialect.