Am I not suitable for Morpheus8 because my C6 was replaced with titanium?

Actually titanium is considered a biocompatible material and is not expected to interfere with the radiofrequency energy with morpheus 8. It should be safe

In general, Morpheus8 is a safe and effective treatment for skin rejuvenation and tightening, even on areas like the neck. However, when it comes to medical conditions such as a titanium implant in your C6 vertebra, caution is necessary.
While the titanium replacement itself is typically safe, the concern from the med spa may be related to the proximity of the treatment area to the surgical site. Morpheus8 uses microneedling with radiofrequency energy, which could potentially affect underlying structures, particularly around the neck and spine. The med spa might have recommended avoiding this area due to the potential risk of impacting the titanium implant or surrounding tissues.
I recommend discussing your specific medical history with both your doctor and the provider performing the Morpheus8 treatment. Your physician can assess whether it's safe to proceed, taking into account your titanium implant and any potential risks. A personalized consultation will provide a clearer answer based on your individual situation.
I hope this helps!