The date of policy change is actually November 18 and the details in the OP are exaggerated. The actual policy is:
Dispute Filing Window
We’re increasing the time for buyers to file a merchandise dispute (Item Not Received and Significantly Not as Described) from 45 days to 180 days. All references in the User Agreement to “Opening a Dispute within 45 days” have been updated to reflect “Opening a Dispute within 180 days.” The Sections these changes appear include the Introduction, 3.15, 13.2 and 13.5.
So, the item would have never been received or the sellers description has to be very inaccurate.
https://www.paypal.com/us/webapps/mpp/ua/upcoming-policies-full
Inaccurate is a question of opinion .
One of two paypal disputes I had was that oil was leaking all over the inside of the lens and it was ruined to the point of no repair ,
There was some oil on the aperature leaves , it sold again to a very happy buyer .
The other was that a lens listed as for parts or repair was inaccurately described , this was a very rare early fuji lens in Leica mount . The buyer wanted a partial refund of 70%
As it was listed as parts or repair and that the buyers complaints were noted in the ad ,
Paypal denied the claim .
So I got ebay negative feedback that stated liar thief horrible person , that was lated removed by ebay .
Still the lens was very rare .
And in my life it is unlikely I will see another .
I offered to take a return if buyer would pay shipping both ways - as it was listed parts / repair but we could not reach an agreement .
On the first complaint the Paypal rep stated that the seller can always relist the item , and without buyers there are no sellers .
Paypal backed the second sale , I still don't know why , it's unlikely to happen again .
Overall with 15 years in and hundreds of sales , the past has been fair to good .
I don't think the future with the new policy's looks to be a sellers world .
I see many new windows for buyers to take advantage of sellers.