Hello Aniduan,
Kāyānupassanā is one of the foundations of mindfulness.
Listen again starting from 30’10”: ‘The reason we are doing this meditation is to discover where is the self; the self that we have so got used to’ (33’17”). During the course of that time he also makes it clear the aim of the meditation is with Nibbana as the goal, not merely as a means towards relaxation and a feeling of general well-being.
I have listened to quite a few of these sermons now several months. Not once did I find anything out of line with pure Dhamma.