Why are you basing medical appliance on such a walled-garden technology you aren't in control of, while there are more accessible alternatives? Oculus was already known for locking up fiascos, this really shouldn't be a surprise for you.
It doesn't help that vendors are generally nervous about liability in medical equipment (this fear is often unfounded, but persistent). As a result, vendors of commercial and industrial equipment generally don't want to engage medical device OEMs with engineering and customization support. If there had been that sort of support in this case, Oculus might have made a custom build without the cert check, just as a de-risking measure.
This vendor reluctance is especially present at the FDA Class III (high risk device) level - most vendors outright prohibit use of their devices in these products. It's an open secret that this still happens anyway in a wink-wink nudge-nudge fashion, just without vendor support - which is arguably worse, but it keeps the lawyers happy.