Pointing out the posts I made 2 years ago when I was a "newbies" is pointless. It's just a blackmail
Rule was existing 2 year back also. If you are not caught at that time it does not make you innocent.
Think if you were banned as newbie then you have nothing to show that you have any "net positive" to the forum.
It is not the blackmail but you can ask for forgiveness.
Is posting relevant articles from external sites with reference URLs against the forum rules? Yes or no?
It is low quality post and forum rules prohibits you to do so. Forum want yours words and discussion and we are not looking for a post that is copied with reference link. If you having nothing to add and discuss on that external site article then you should not post them. (though adding link will not get you banned.)
You can use external site link if it is relevant to your original answer, give some facts to your answer or increase the weight of your answer.
We all get better and smarter by growing old. What I mean here is the version of me today is different from the version I was 2 years ago. By the way, posting relevant articles from external sites was not all I did, is it? I posted some good quality contents too in the past. The reason why I like sharing trending contents (hot topics) from external sites is because I want to see people reactions and what they actually think about it.
Example: BitFinex vs. Tether issues now, it's a hot topic (the most trending) and if you look around you might see almost zero discussions about it. This is the biggest crypto community in the world and how could nobody is talking about the latest news, what's happening in the cryptocurrency ecosystem?
But if nobody likes sharing the latest updates/articles about the cryptocurrency, even if it's not against the forum rules it's totally fine with me. I believe some people are using that as an evidence to destroy my reputation here. Well, from now on it's over. It's better to write only what's in head.