Singapurcanac,
audio records of 1 month old is not the plane glideslope.
The true plane glidescope is in black boxes other - speed and regimes used. Surely, combined with the audio-record (not this one. but the one resulting from the work of Poles in Moscow for a month, identifying their voices) - gives a much fuller picture - combined with the plane's technical devices' records.
What I mean is Poland is aware of the plane's technical devices' record, and for a month as min already.
AND Poland has their own 3rd black box - reading the same engines' work parameters, etc. The own Polish installment, additional to the ordinary black boxes' plane set - that Poland took home the first thing - right on the crash site. Doubling the technical info held in Moscow.
There can't be any fooling around with technical data from the plane - it was recorded by different devices, in parallel - and is kept respectively in Moscow and in Warsaw. Neither side will trick with that.
If the resulting picture, of the plane's glidepath and aerodrome neglecting to see the plane's position timely - their duty indeed - pointed at the ground control mistake - nothing on Earth would have stopped Poland during the last month of releasing that news.