Kind of. It’s not that it’s weaker, it’s that it’s route into cells is less damaging, and so it’s less “severe” , though the article contradicts itself on that particular word.

FTA: “ this alternative entryway likely causes less damage inside the lungs”

"Omicron may be a small step back in severity. But it's probably more severe on its own than the original version of the virus,"

Before omicron came along, SARS-CoV-2 was actually evolving to be more severe, says Bhattacharyya, of Harvard Medical School. "We're looking at a virus that's gotten progressively more severe over time," he says.