Coronavirus: Causes the Brain to Shrink?

I've read a lot about various long haul symptoms from COVID-19, but I think this is the first time I've read about a study that suggests that the brain shrinks. Now I've read about impacts to the brain via brain fog, but a shrinking of brain size? Ouch. 

Fox News via Yahoo (Jun 18) reports:

Researchers affiliated with the University of Oxford posted findings ahead of peer review this week to medRxiv, drawing on data from the U.K. Biobank. They compared brain scans taken pre-pandemic to scans taken about three years later among 394 coronavirus patients and 388 matched controls. A further analysis included 15 hospitalized patients compared with 379 people who hadn’t been hospitalized.

"Our findings thus consistently relate to loss of grey matter in limbic cortical areas directly linked to the primary olfactory and gustatory system," or areas in the brain related to the perception of smell and taste, authors wrote.

So perhaps this is why people are having a loss of smell and taste?

LA TImes (Jun 21) highlights what Dr. Scott Gottlieb said on Face the Nation:

The study‘s results were mentioned by former Food and Drug Administration commissioner Dr. Scott Gottlieb on the Sunday news program “Face the Nation” on CBS as another example of why it is so important that unvaccinated people get inoculated. The results also underscore how evidence is mounting that people can still suffer from illness related to COVID-19 many months after infection, a condition known as “long COVID.”

“Certain areas of their brain showed a decline in actual tissue — a shrinkage of parts of their brain,” Gottlieb said on the news program. “It’s very concerning because it does suggest that the virus could be having a direct effect on certain portions of the brain. ... And I think what it suggests is that the balance of the information that we’re accruing does indicate that COVID is a disease that could create persistent symptoms.”

From what I've read, people do get their sense of taste and smell back so does the brain just re-wire itself after shrinking?

The abstract states that "it remains unknown however whether the impact of COVID-19 can be detected in milder cases" as it didn't focus on those individuals. I do have one specific question about the study: was the shrinkage in the brain associated with all those who came down with COVID-19 or just a portion of them? I scanned through the actual study and couldn't find anything about that. One scary fact while doing a word search, "The loss of grey matter in memory-related regions of the brain may in turn increase the risk of these patients of developing dementia in the longer term." Nope, don't want that.