As an aside, and I must emphasise this is not a criticism but merely an observation - Phil Lowe's appointment continues the tradition of internal candidates filling the middle to upper levels of the RBA. I may be mistaken, but for more than 20 years, every appointee to Governor, Deputy Governor and front office Assistant Governor roles have been internal appointees - the only exception I can think of even before then was the appointment of Bernie Fraser to Governor in 1989. And Bernie was appointed from Treasury Secretary so he was hardly an outsider.
This is probably - no almost certainly - not an issue at all, given the structure of the RBA Board which has the Treasury Secretary as an ex officio member and six other non-bank staff. This diversity of the Board has worked extremely well for two decades as different views outside the mainstream of the RBA are brought to the table when policy is discussed each month.
All up, Australians can rest assured that the RBA remains a world leader and a fiercely independent and professional institution. I'd be willing to bet a few Aussie dollars that come what may it will meet its inflation target over the next 5 or 10 years and adjust interest rates whenever it sees fit.