Here is an article about the treatment you mention.
Ohio stem cell procedure offering hope to NFL players with multiple concussions | fox8.com
It is a fat stem cell therapy.

The challenge with it and many other treatments is it appears it might be needed early in the process, rather that late in the PCS process where spontaneous recovery did not manifest.

NFL players can afford a $8,000 treatment with every concussion regardless of whether their symptoms are prolonged.

The rat study shows the treatment needs to be started in the first 2 weeks.

Many treatments have shown to help if started early but of no or minimal value if started later in the concussion process.

With 1.5 million concussions that are reported to hospital ER's each year, the cost would be $12,000,000,000 or $12 billion dollars. That does not even include the millions more that never get reported to ER's. The estimate is there are 3 to 5 or even 6 million concussions each year.

These treatments would need to become much more affordable before health insurance companies will be willing to pay for them. PCS is not a life threatening disease by normal standards.

If 85% of concussions recovery spontaneously in the first 6 weeks, treating concussions before that 6 week window is finished will be hard to justify.

If the therapy could be done for less than a $1000, it may be accepted as a worthwhile preventive treatment during the first week.

A BIG challenge will be the diagnostic criteria of those concussions that qualify for such early treatment.

They are just entering Phase 2 Clinical Trials. It will be interesting to see what they learn.