Almost everyone who's committed to scientism wouldn't say that that's what they're committed to. "Scientism" is a pejorative term.

In any case, scientism isn't relevant to disagreements about whether there's good evidence of life after death. The scientism issue is about a conflict between the sciences and the arts.

Regarding the reports about life after death, the questions would be empirical: How good are the studies, as in how scientific and objective are they? Were the individuals fully dead or were they only in a coma, their brain still alive? Do they come back with knowledge they couldn't have had unless they'd still been alive even though their body was fully dead? Have the reports been peer-reviewed? Is there a simpler explanation of their personal transformation?

I haven't looked deeply into the reports. I doubt, though, they'd pass scientific muster. Consciousness is very mysterious, but the notion of personal survival of death seems too Christian and American (egoistic) to be true.