Hmm, I think it's a non issue to be honest. The Buddha talked about how there are 84000 different dharma gates for people to enter, 84000 different ways of finding one's way. I see secular meditation, akin to Jon Kabat-Zinns MBSR method focusing on meditation as a way to tackle chronic pain and other ailments, as just being one small step towards someday or in some other lifetime come to full realisation.
If someone claims to have invented it, sure, there might be an issue of appropriation, but most just decline to mention the religious context it originated from. Which I think is fine in order to reach more people. Just my take!