The Reddit accounts are not new

Eg, 6 year old account https://www.reddit.com/user/lamka02sk/ Or 2 years https://www.reddit.com/user/SoftGreener/ 4 years https://www.reddit.com/user/omerby12/comments/

There are thousands of dormant accounts, the other day I found one dormant for 5-6 years, became active 1 year ago and had 95k comments! Most bashing the west and defending Russia and populist regimes

Those are not usernames, but auto-generated ids of the linked comments/posts. The rest of the url is just a human readable title, which you can erase and still get to the same post.

and this is how fake news is born....

These are the reddit thread ids which have "similar namess". The users behind them have different names and have been active on the network for up to 6 years.

Those aren't user names.