few things about it:

1) some of the people involved accepted the authenticity of these recordings(some directly, some logically)

2) the recordings that were denied being authentic were investigated by audio forensic experts and they reported that these are real.

3) the pro-government media tried to scam US based audio studios to get reports to falsify these recordings. for an example, the mainstream pro-akp media used a report by Kaleidoscope Sound which was later denied by the studio. You can read their public statement here: https://www.facebook.com/KaleidoscopeSound

4) Other evidence brought to light by the opposition party supports the authenticity of these recordings.

5) These recordings are part of the legal prosecution.

Though there were some recordings that were made illegally, the fact that the ruling party actively blocked the legal prosecution lives no choice for the public to learn about the accusations from the whistleblower.

If the legal process was not blocked it would have been better to wait for the outcome of the prosecution, but in this case we don't have choice.