"New normal" is literally the term that has been thrown around unironically. It's a real thing that has really been said in this context, not a strawman.
Since 1950, we've never had a Moderate+ El Nino later in the year when the March SOI was >+2.1 (9 examples)
Through March 19, the 30-day SOI average is +12.6, March so far being +14.
I agree with his point.
"New normal" is kind of a strawman IMO that seems aimed to undermine the idea that these types of extreme outlier events can and do signify legitimate baseline shifts, and represent a logical continuation on a longer trend line. There will still be natural year-to-year variance to some extent of course, but these outliers will form another step in the staircase, so to speak. And then obviously these outliers will continue to become more and more common. Whether you want to quibble over defining that as "normal" or not won't change that fact.
And you see it with global temperatures pretty clearly. There's been a pretty clear global baseline shift with each successive major NiƱo event over the last 30 years. You see it with 1997-98, then again with 2015-16, and now seemingly once again with 2023-24. Global temperatures will simply have a very hard time reaching back below pre-2020 levels for the foreseeable future.
https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature
On a seasonal and regional scale that year-to-year variance will likely still be more pronounced, but it's perfectly logical that it would largely follow that same progression.