Yeah. When my dad had a kidney failure I had a lot of fun proving to the doctors that I did not in fact love my dad, and that's why I was giving him a kidney.
Really though, the definition of "compelled" is fuzzy, and mostly for medical stuff we take "consent" to mean "sound of mind" and "not overtly coerced, i.e. by threats of violence or such".
Is someone able to "consent" if they're only donating blood or a kidney because their religion tells them to do good? That sounds like a cult, huh. What about because they love someone? What about because the local blood drive literally gives you 10 bucks and a candy for donating blood?
Like, you can argue around enough and say everyone is always compelled at all times by "society" or "their upbringing", but that's an obviously useless definition.
What we have now, you getting a private meeting with a nurse or such who asks "are you really sure? Is anyone making you do this?"... that, plus doing basic mental health checks of "does not have dementia or mental retardation", that seems like it should be enough for any real situation.
Trying to say "No, someone who's famous might be doing this to write a blog post about it, that's not okay" is an interpretation of consent that simply is too far gone to be useful.