"This is a truly remarkable discovery, and is the most important piece of prehistoric art to be found in Britain in the last 100 years. ..."
From the article
From the article
Your full quote provides the important context included in the original statement, “most important…to be found in Britain”.
Is it more important than the 30,000+ yo mammoth carving recently found in Swabia? Debatable, but the article never claimed it was contending for such a designation.
I'd wager a hard no.