The Nazis were genocidally anti-Slav.
It goes without saying that if Nazi Germany won WWII, most Ukrainians would have been exterminated. Any survivors would have been enslaved and Germanized, their culture and history being violently stamped out.
CalBear (who famously did a lot of research for his AANW timeline) has pointed out several times on this site that Generalplan Ost called for the murder of 65% of Ukrainians, 85% of Poles, 75% of Belarusians, 50% of Czechs, and 75% of Russians. Entire cities would have been demolished BY HAND (this was called "extermination through labor").
The areas forcibly depopulated by the Nazis would then have been settled by the Germans.
The Nazis were evil incarnate. Their cruelty and savagery was literally unprecedented in human history.
This is a vast overgeneralization. Nazis were only Nazis when they wanted to be Nazis. Nazi leadership handed out honorary Aryan status like free candy, allied with Italians, Asians, and Muslims, and were more than willing to overlook ideology on countless occasions when it was practical, convenient, and/or profitable.
I agree. The argument that it would be 'Notzi' - and therefore implausible or even ASB - for the Nazis to do something outside their dogma isn't supported by their actions.
Besides they can still have genocidal objectives whilst also exploiting the hopes and fears of those people they want to genocide. Plus they would be contradictory or hypocritical in some cases depending on whether it was the personal, or practical or politically and diplomatically advantageous.
Hitler's chauffeur, and an SS member, was a Ruhr Pole.
The No. 2 member of the SS - after Hitler as No. 1 - was a mischling.
One of Goering's senior deputies was a mischling - or wasn't if you believe his excuses for not being.
Heydrich ensured a Jewish fencing rival was able to leave to the US.
So when it came to the personal they could be 'Notzi' in OTL.
When they were scrounging for votes pre-takeover they produced materials in the Slavic Masurian dialect to win votes in southern East Prussia.
The Russians were Aryans to some of their intellectuals but had been bastardised by interbreeding with Asiatics and therefore subhuman. Yet the Asiatic Japanese were honorary Aryans.
They even had similar views of the Chinese until it wasn't in their interests to do so. Chiang Kai-shek's adopted son was a Wehrmacht officer up until 1939.
Depending on what Gauleiter an occupied Pole found themselves under saw some become German at a stroke of a pen. The greatest single source of recruits for the western Free Polish forces was deserters and prisoners from the Wehrmacht.
The Nazis created two Slavic states Slovakia and Croatia. They recruited Ukrainians and Belarusians as auxiliary policemen.
So I wouldn't say it's implausible that they could have taken a different tack with Ukraine, Belarus and the Baltics. As said above Rosenberg even suggested it but since Hitler was at the height of his megalomania he opted for the Himmler Kool-Aid. Rosenberg got a full house at Nuremberg so I don't think he could be called a 'Notzi'.
If they had taken the Rosenberg route - of giving Ukrainians, Belarusians and Balts a *sense* of control - they could have maybe pacified their rear and had a greater reservoir of military manpower.
As it was they alienated a lot of them through almost instant repression. Then they belatedly realised they could exploit their national feelings with a puppet Rada in Belarus and a Ukrainian SS division. But by that time it was too late.
And those latter actions show they could have gone this route but screwed up because they were high on their own Kool-Aid.
EDIT: Addition. There's even a case of a concentration camp commander being tried and executed on charges that included ... 'premeditated murder'.
en.wikipedia.org