You wrote that Soviets wanted to assimilate / integrate Polish officers.
And now let's check these definitions:
"Cultural assimilation is a socio-political response to demographic multi-ethnicity that supports or promotes the assimilation of ethnic minorities
into the dominant culture"
A few pages ago you denied that Polish officers were a national (ethnic) group?
Yet you write that Soviets considered them as an ethnic minoriy.
"Social integration, in sociology and other social sciences, is the movement of minority groups such as ethnic minorities, refugees and underprivileged sections of a society into the mainstream of [these] societies.
Members of the minority groups thus gain full access to the opportunities, rights and services available to the members of the mainstream."
Polish officers were not part of the Soviet society. Were they?
How can you integrate enemy war prisoners into your society? This is a bit like slavery.
Slavery was also all about "integrating" enemy war captives into one's society.
That is called assimilation or integration. Genocide specifically deals with physical destruction.
The intention was to destroy the Polish officers as a specific group - either by Sovietization or physical destruction.
Were the Polish officers finally Sovietized or physically destroyed?
The answer is - physically destroyed. So this was a genocide.
Insofar as Soviet authorities were concerned they were “contra”.
When you murder a person because you think he was a "bad guy", does it mean you are not a murderer? If this was true then most of murderers wouldn't be guilty for their crimes.
USSR being a sovereign state obviously had the right to recognized (or not) whoever it wanted.
Theoretically speaking, yes.
But ignoring reality in international law can't be used for justification of crimes and has some limits.
You told that the USSR recognized the Polish state as non-existant (probably yet on 17 September 1939) and that's why it did not treat the Polish POWs taken in 1939 as POWs should be treated.
This means that not recognizing facts was an excuse to commit crimes.
Such behaviour is still a crime of the USSR (and of course I know that you don't try to deny this fact - we just argue about the character of this crime, if it was a war crime or rather a genocide).
I can say that Poland being a sovereign state obviously has the right to recognize Katyn as a genocide.
They were killed because Soviet Authorities considered the to be enemy of existing reign.
It is obvious that soldiers of enemy regime who are captured by soldiers of another regime during a war between these regimes, are their enemies. But only as long as they are fighting.
After being captured, they are no longer enemies - they become war prisoners.
And while imprisoned in Soviet POW camps Polish officers did not pose any real threat to the Soviet regime.
Claiming they posed a threat could have been an excuse used to murder them for another, real reason.
No it does not; in order to comply with that definition they would have to be killed for being Polish.
In international law intentions don't matter, only facts matter.
Why intentions don't matter in international law?
Because it is hard to prove what were intentions of a state - states as legal persons (immaterial, fictional) don't have any intentions, and physical persons who represent states can have different intentions each.
So there are no proofs that all of murdered Polish officers were anti-Communist.
That is fine because nobody tried to prove that they were. Ones again -insofar as Soviet Authority were concerned they were Anti soviet.
Certainly Soviet authorities were also concerned they were Polish and important for Poland. There is no doubt.
So how can one be certain that they were killed because the Soviet authorities were concerned they were anti-Soviet, or because the Soviet authorities were concerned they were Polish intelligentsia / military elites / leadership?
do you think that if Poles were ardent communist they would suffer the same fate?
And do you think they would? We don't know, what would have happened.
As I wrote - facts matter, not thoughts.
False logic. Leon Trotsky was an ardent communist but yet he was murdered by Soviet agents. Same with those communists like Yagoda and Zinoviev
All 3 of them were considered enemy of Soviet state – just like Polish officers -and that is why there killed.
So now we can see that being ardent communist was not an obstacle for being enemy of the Soviet state.
Poles could be ardent communists and at the same time enemies of the Soviet state, like Trotsky.
They could be enemies of the Soviet state for example just because of being Polish elites. Pre-war Poland as a whole was, after all, an enemy of the Soviet state (and Ukraine / Belarus) - according to the Soviet regime.
Well quite a few of them switched sides actually; then again quite a few of them did die.
Mortailty rate wasn't 99,99% among them, like among those from Katyn.