Unfortunately, the review doesn't give a direct, like with like, comparison. To show any differences or similarities, a more scientific approach could have been taken, where the same shot with the same exposure is taken side by side for Pan film & Kentmere. It's not that difficult to organise.
Otherwise, it is just the reviewer's opinion.
Looking at the Massive Development Chart, the times for Pan 400 and Kentmere 400 are quite different, so I am satisfied that they are different emulsions.
The developing time for Pan400 in Ilfosol 3, at 1+9 @20C is 6:30 in digital truth
The developing time for Kentmere 400 in Ilfosol 3, at 1+9 @20C is 6:30 in digital truth & Kentmere technical information sheet from Ilford
I notice that the Kentmere technical information sheet has the following:
Kentmere Pan 400 heading.(is this a hint???)
https://www.ilfordphoto.com/amfile/file/download/file/1922/product/697/
I have never shot either film, but I do know that making film emulsions is a complicated and expensive business.
So I would ask the question, why would Ilford make 3 different emulsions when they could make 2 and repackage one emulsion under different names. It would make economic sense, especially in a business where margins are very tight.
It's a bit like the Ilford XP2 super & Fuji Neopan 400CN debate.
A lot of what we hear is marketing talk. The same snake oil but in a different bottle.