While the original article could come under the ‘Fake News’ heading, there are still some good learning points to take in. The following is from UK Airsports, and refers to the original posting about Aluminium Carabiners:

This is part of an OPINION piece from a French club loosely based on an official FFVL investigation, cherry picking info to back their opinion without reference to the conclusions of the FFVL.
There has been a lot of misinformation, speculation and debate on forums about it.
Carlo wrote a answer to Andy Wallis on the Derbyshire Club Facebook Page which I agree with and will quote.
As Carlo posted:
this "Avis de navigabilite" (which translates into "Opinion of navigability) document published by 'Les Toiles du Sud' (which seems to be a freeflight club in southern France) appears to be just that i.e. just someone's opinion, not an official safety notice based on thorough investigation, imho.
This doc appears to be a rehash of the real safety notice published by the FFVL (Federation Francaise de Vol Libre, the French equivalent of the UK's BHPA) in Dec 2018, following FFVL investigation, but with the FFVL's conclusions removed. For example, they do not conclude that pilots should not use alu karabiners, or that these failures are down to design or production flaws in the karabiners.
The main conclusions of this FFVL investigation were:

Never use karabiners designed for solo use for tandem use;

Check/verify your equipment (and inspect it regularly);

Do not use alu karabiners for more than 5 years or 500 hours maximum, whichever comes first, from first use;

Alu karabiners which are older than 5 years, have more than 500 hours use, or are not in good condition should be removed from circulation;

Pilots should ensure that their karabiners are neither too old nor over-used nor in poor condition;

Do not connect reserves with alu karabiners;

Pilots to circulate this info.
There is also some mention of alternatives (soft links, pin lock, steel karabiners, maillions) and their pros and cons.
Link to the original FFVL safety notice (PDF, 391 KB) http://bit.ly/39C4R34