Even some Christians think that these stories of visits to heaven lack authenticity.
Here is what a well known Christian who focuses on the meaning of scripture thinks. Reference: John F. MacArthur
We live in a narcissistic culture, and it shows in these accounts of people who claim they’ve been to heaven. They sound as if they viewed paradise in a mirror, keeping themselves in the foreground. They say comparatively little about God or His glory. But the glory of God is what the Bible says fills, illuminates, and defines heaven. Instead, the authors of these stories seem obsessed with details like how good they felt—how peaceful, how happy, how comforted they were; how they received privileges and accolades; how fun and enlightening their experience was; and how many things they think they now understand perfectly that could never be gleaned from Scripture alone. In short, they glorify self while barely noticing God’s glory. They highlight everything but what’s truly important about heaven.
It seems to me that these accounts of visits to heaven are based on a modern feel good hand clappers theology that has little in the line of a scriptural basis.