Space aliens are still kinda the best explanation. It's extremely inconclusive, and it's entirely possible that we'll discover some new natural phenomenon to explain it instead, but for now there's not really any known alternative.
https://www.skyatnightmagazine.com/space-science/wow-signal-...
This is a follow up to a September 2024 paper (the article you link is November 2024)... "Arecibo Wow! I: An Astrophysical Explanation for the Wow! Signal" by Abel Méndez, Kevin Ortiz Ceballos, Jorge I. Zuluaga (just those three).
The research in the article does suggest a plausible alternative
At some point more this shifted to the divine being an entirely separate supernatural domain.
https://en.wikipedia.org/wiki/Calculating_God?useskin=vector
There are many, many cosmic processes that we don't know the first thing about.
At one point, we didn't know what a pulsar was, and a fair amount of people probably thought it was an alien signal.
Human History is littered with examples of attribution of the unexplained to aliens.
So far, non alien explanations have been found for all of them, except possibly this one.
Does it warrant further study? Absolutely. Is it likely to be aliens? Statistically, no.
We probably wouldn't even recognize real aliens because we'd be too busy looking for our own reflection in the sky.
They might have learned different things than we have, they might know a lot more about our universe than we do, but I'd guess that much of what we've managed to learn so far will still be a part of their reality regardless of their level of familiarity with it. For example, more than 90% of the atoms in the universe are hydrogen. They might have discovered things that are more exotic and never seen on Earth, but the hydrogen atoms we've studied won't be any different from hydrogen they'd have studied. We share a home. By the time they've figured out enough of how the universe works to reach us it's pretty likely that we'll have some common ground to talk about.