If 607BCE is the wrong date for the destruction of Jerusalem, then 1914 has no relevance, neither does 1919, neither does the Faithful and Discreet Slave a.k.a the Governing Body of J.W's, have any relevance, authority, right to interpret scripture for others, or anything .
No 607, no 1914, no 1919 = No FDS. ............ Simples !
p.s There is not one credible piece of supporting evidence for 607BCE as the date for the destruction of Jerusalem by the Babylonians, which took place 20 years later, 587/6 BCE