Given it mentions Angela Rayner is still mired in transactivism and also that she has the potential to be the first female leader, I would be very wary. That said, Labour have never had a female leader, so it’s not as if they’re likely to elect one any time soon.
Harriet Harman turned into a decent enough politician, having been (with full hindsight) bizarrely swayed into supporting PIE. Lisa Nandy may well have been swayed by young Labour, or whoever. It’s pretty obvious that happened in the SNP, where young people were highly valued and thus the situation was ripe for infiltration.