These are instructions to locate the login cookie for YouTube that’s stored in your browser so that you can import it into OPs program. Start with the network tab of the browser’s dev tools.

100%. From the arstechnica piece:

Making Old Reddit users log in could impact Reddit scraping but also will address Reddit’s interest in connecting as much traffic as possible to specific users—a strategy that is common among companies like Reddit that rely on advertising for revenue.

I just found this out naturally and immediately came to lemmy to see if someone’s posted about it.

Seriously I don’t want a reddit account and old.reddit.com without logging in has been a great way of checking up on the odd thing without having an account and being stuck in the dark patterns that keep you engaging