Many have compared the differences in standard (news broadcaster) accents in of Taiwan 國語 and PRC 普通话 to the differences in British and American accents. What linguistic factors have contributed to the divergence in these accents (particularly, what has caused Taiwanese-accented Mandarin to sound noticeably different) and when did this divergence become noticeable? Did the divergence begin/accelerate following gradual relaxation of KMT rule in Taiwan in the 1980s?
Some clarifying points to hopefully save this question from being closed as too broad:
I am focusing on "standard" speech of CCTV/NTBS news anchors - which doesn't differ as much within either country (i.e., the speech of any two news anchors within either PRC or Taiwan will not diverge as much as the speech of any two people in the larger populations), yet is is notably different between either country (i.e., the speech of a news anchor from PRC and another news anchor from Taiwan will consistently diverge, likely in predictable ways). The difference is particularly obvious when CCTV4, for example, includes snippets from Taiwanese news outlets narrated in speech that differs markedly from that of the PRC anchors. A stab at cross-strait comity that ironically brings to mind the gap.
My interest is that since KMT pushed 國語 repressed use of 台语 as part of a political agenda following their retreat to Taiwan, one would think that they would have used news broadcast speech as a tool to advance this political agenda, in a similar way as the PRC does now (in the PRC case, perhaps more a desire for linguistic unification than oppression, per se). Given the origin of KMT from Mainland (admittedly, many parts of Mainland), I would like to know whether the speech Taiwan news anchors of 40-50 years ago is (a) markedly different from the speech of modern Taiwan news anchors ; (b) if so, was it more similar then to the speech of modern PRC news anchors ; (c) if so, when did the divergence begin.
One alternate possibility to a growing divergence over time wrt news anchor speech is that from the beginning, in Taiwan, the KMT came up with a different conception of what standard 国语 should sound like, and that standard, enforced from the getgo, was already divergent from what is currently spoken by news anchors in the Mainland.
I was simply not around when all of this was/not taking place, so am curious to hear from folks who were.