I don't think that conflicts with the doctrine that we survive the death of the body.
"I think, (therefore) I exist/am"
According to Meditation 2, Descartes says that the only thing he knows with certainty is that due to our ability to think, we know we exist.
Through our consciousness, we exist.
This then leads me to the following question:
Is artificial intelligence considered consciousness?
If it is, then the statement holds true. If it isn't, there lies alternative possibilities for the conception of knowledge.
The Radical Skeptical Theory states that the reality all of us perceive may in fact be an illusion to what is TRULY reality. (Ex - Brain in the Vat, The Matrix, God or an evil spirit deceiving us).
Through the examples listed above, the human mind is being deceived. However, through the concept of AI, it is possible that a "robot" or any other form of machinery with AI is being deceived (or programmed) into perceiving reality the same way we perceive it.
Descartes is false since there lies the possibility that our lives may be interpreted not only through a MEANS of AI, but AI itself.
A robot may be simulating a life through its thought processes, and it is possible that I am that robot itself.
It conflicts with the idea that we survive as disembodied spirits.
Yes. The problem is that although Descartes was a dualist, he believed that the person is identical with his mind, but not with his body. So if the mind survives, so does the person. This is, of course, Platonic, and Descartes wanted to revert to Platonism, and discard medieval Aristotelianism. I don't know enough to know why Descartes's works were placed on the Index ("pending revision") but this may well be one of the major reasons. I agree with you now.