I haven't read the article yet so unsure of the context where "releasing the fascia" is used, however at least in fitness related practices, it means relaxing t

I haven't read the article yet so unsure of the context where "releasing the fascia" is used, however at least in fitness related practices, it means relaxing the tension in it - whether by applying tension to it say with yin yoga postures where you support the muscles with bolsters, blocks, or are in positions that aren't engaging them - and where you maintain a somewhat uncomfortable stretch into fascial layers. So releasing a muscle that's tight would be a similar idea.