[tiwil]

If that event of June 24 really existed, why bring it up now?  What is the motive behind the article?  And how true are the facts?

It's actually 2017 article, pretty old but still the same. People bringing this "fact" to public to show that Telegram doesn't use E2EE on normal chats. They (as the link I posted in previous post) only use E2EE in secret chats. There is no claim from Telegram that they use E2EE on normal nor group chats.

Also the article doesn't say that Signal is not encrypted. They only say, "Once they learnt that it was being tracked, they tried to shift to another encrypted app called Signal". For me, the article means that they was tracked by Telegram then moved to Signal since it's an encrypted chat app.
Therefore, this article says that Signal has encrypted chat so ISIS doesn't get tracked whenever they wanted to communicate. While on the other hand, Telegram doesn't have one since they can track down ISIS.