is there a reason, other than general faith in humanity, to assume those '1573 sessions' are real?

I do not see any link or source for the data. I assume it is to remain closed, if it exists.

it's reasonable to note that w/o sharing the data these findings can't be audited or built upon

but i think the prior on 'this team fabricated these findings' is v low

Its our own sessions, from our team, over the last 3 months. We used them to develop the product and learn about our usage. You are right, they will remain closed. But I am happy to share aggregated information, if you have specific questions about the dataset.