I do agree with the conclusion. - A new mission dedicated to answering the question of life on Mars is warranted. Earthbound discoveries of extremophile microbial life in the past decades have broadened our definition of life-enabling environmental conditions and discoveries of new classes of only intermittently alive cells/spores have broadened our definition of life itself.

Plus, apart from satisfying our curiosity, we will very likely get some insights into our own biochemistry along the way.

Worth noting the article argues we killed life on Mars inside of a sample taken, NOT all life on Mars.