Whatever agreements and concessions end up being made by either side, signaling the willingness to give up (an unlikely immediately helpful) NATO accession is a strong sign by Zelensky that he's ready to talk business in actual negotiations.
Giving up the major pretext for the "special military operation" is also a pretty clever opening towards Russian public opinion, which is going to make it harder for Putin to claim Russia victimhood.
This early in the war also bears thinking about as well. Right now, Ukraine has an unexpectedly strong hand, so would be negotiating from a, relative, position of strength. Military analysts are - which would have been unthinkable a month ago - speculating that maybe, just maybe, the Russian invasion will grind to a halt.
But that's very much a maybe: it could also swing the other way. However, in case of slipping fortunes, Putin's and Zelensky's positions are not symmetrical in negotiations: as a dictator, Putin can, at least in the short term, ride out military reverses much more easily than a democratically elected President facing massive civilian deaths at home.
The book length version:
NATO accession has been widely seen as problematic and too adversarial towards Russia. It may have been a partial cause to the current invasion - I say may despite Russia's public statements because, with Putin, there is no telling when he's telling the truth or not.
A democratic, unitary and economically successful Ukraine may be too much for Putin to stomach next door, mostly as an indictment of his domestic failures. The fact that the 2014 crisis was about Ukrainian EU - not NATO - membership shows the limit of NATO membership being the only cause.
Here's what an invited guest writer, John Mearcheimer, for the Economist - hardly a pro-Putin mouthpiece - had to say. It's way too pat in blaming it all on NATO in my opinion, but there are some good hard truths in it nevertheless (note that the Economist distanced itself somewhat by making the guest editorial aspect quite prominent):
The trouble over Ukraine actually started at NATO’s Bucharest summit in April 2008, when George W. Bush’s administration pushed the alliance to announce that Ukraine and Georgia “will become members”. Russian leaders responded immediately with outrage, characterizing this decision as an existential threat to Russia and vowing to thwart it. According to a respected Russian journalist, Mr Putin “flew into a rage” and warned that “if Ukraine joins NATO, it will do so without Crimea and the eastern regions. It will simply fall apart.” America ignored Moscow’s red line, however, and pushed forward to make Ukraine a Western bulwark on Russia’s border. That strategy included two other elements: bringing Ukraine closer to the EU and making it a pro-American democracy.
These efforts eventually sparked hostilities in February 2014, after an uprising (which was supported by America) caused Ukraine’s pro-Russian president, Viktor Yanukovych, to flee the country. In response, Russia took Crimea from Ukraine and helped fuel a civil war that broke out in the Donbas region of eastern Ukraine.
The next major confrontation came in December 2021 and led directly to the current war. The main cause was that Ukraine was becoming a de facto member of NATO. The process started in December 2017, when the Trump administration decided to sell Kyiv “defensive weapons”. What counts as “defensive” is hardly clear-cut, however, and these weapons certainly looked offensive to Moscow and its allies in the Donbas region. Other NATO countries got in on the act, shipping weapons to Ukraine, training its armed forces and allowing it to participate in joint air and naval exercises. In July 2021, Ukraine and America co-hosted a major naval exercise in the Black Sea region involving navies from 32 countries. Operation Sea Breeze almost provoked Russia to fire at a British naval destroyer that deliberately entered what Russia considers its territorial waters.
To be clear, while I am including the third paragraph above, the West has been reacting to Russian aggression since 2014, not causing it (unlike what this claims).
Ultimately, Ukraine is getting aggressed, this is Putin's war, and the blood from the methods being used to wage it are on Putin's hands. But few disputes are entirely one sided and it is hard to see how the US's constant whining about Cuba during, and even after, the Cold War can be reconciled with its expectations that Russia should just roll over with regards to large NATO border neighbors.
Point is, there may be a middle ground where Ukraine is free to carry out its foreign policy as it sees fit, but is not member of what's for all intent and purposes, and especially right now, an anti-Russia alliance.
The, remote, possibility of NATO accession has not solved the present problem so it might be good to change course. NATO has in any case been very supportive of Ukraine, within the constraints of nuclear escalation risks, so Ukraine hasn't been left out.
p.s. if it's the same Mearsheimer that authored a book about Israel-American relations that I read, be aware he's controversial (to say the least) at times.