Could be. Very strange, but ultimately not relevant at all to this board. Though not wanting to be unkind. But I believe that this is someone who wants attention, who wants to be the center of attention, and will do and say anything to get it. Could be he has some brain injury that has caused this behavior. Hard to know.
Sounds like he had some infection, possibly some other tumor type maybe, but he never actually had GBM. He never got more than a few weeks of “treatment” and he claims he ended it, not that hypochondria was exposed, perhaps.