I never was a JW, yet I am aware of the '1975' debacle (as I am aware of the 'Beth Sarim' for 'returning princes' fiasco and others).
It seems to me (though I stand to be corrected) that WTBTS - as ever - wish to rewrite their history ;'1984' style, failed prophecies being just one aspect of it. Once upon a time, that was easier than it is today. Here on JWN we have eye-witness testimony, always crucial, and enough of it to be historically significant.
As an outsider, my view is that the more evidence of their history, whether by recorded eye-witness testimony, recorded documents, etc., the better.
During a recent FS visit to my house a JW who claimed to be an elder and to have been a baptised JW for nearly fifty years claimed to have no knowledge of any significance of the year 1975. I told him that there was no point in talking to him because he was either dishonest or had no knowledge of the WTBTS.