We're entering a bit of uncharted territory when it comes to El Niño And La Niña (simplified explanation, El Niño hotter and La Niña colder). Normally they last about 9-12 months. We Just exited a triple dip La Niña (2020-2023), and the last one was 1998-2001, and before that 1973-1976. Now in the past this multi year La Niña followed a strong El Niño, and scientists had a few theories that mostly revolved around the planet cooling due to thermo differences across the surface. The issue with this recent La Niña is that it did not follow a strong El Niño, and the La Niña effect caused the jet stream to weaken significantly in 2023, it is very important for cooling different areas of the planet, weakening hurricanes, and many other things. Right now we're in a neutral state and likely to shift over to an El Niño later this year. Meaning what we've seen as of late could be a good bit worse when El Niño occurs.

We are also in a time period where the solar cycle is peaking (most likely to peak in 2025). While we're not exactly sure about the climate impacts of the solar activity, we do know it means more storms and magnetic waves hitting the Earth, and with global warming our atmosphere has expanded a bit and there could be more unexpected effects such as issues with GPS, aviation, and satellites..

All in all we're not entirely certain as to why 2023 was that much hotter and there are many theories, , but based on history we could experience a significantly hotter 2024. Also, if the trend continues it could mean that's 2023 was a freak year for us, but in the future it could become the norm.

I know this doesn't really answer the question, but at the moment there is no finite answer. However, due to these irregularities occurring it does not look good down the road and we won't know for certain until it happens.

Every year being the hottest year on record has been the norm for awhile now…

Air and sea temperatures, ice shelf thickness etc. going back to fit perfectly with the current models and 2023 going down as a "freak occurrence" is, at least in my opinion, highly unlikely.

But it's also missing an important point: this is a scientific problem and realizing that we were not able to predict what could potentially happen in just a few years in the future, is worrisome in its own regard.
"Uncharted territory" basically means that scientists confirm it's anybody's guess what is going to happen next, since they don't understand why it's happening in the first place.

"It could imply that a warming planet is already fundamentally altering how the climate system operates, much sooner than scientists had anticipated."

Could be an anomaly on top of climate change but as far as we know it's probably hard to tell. We'll probably understand it better in a few years.