The key is the IAF. Doc 8168 specifies only the +/-30 if
no IAF exists.
Reference:
Chapter 3 INITIAL APPROACH SEGMENT
3.2 TYPES OF MANOEUVRES
3.2.1 Where no suitable IAF or IF is available to construct the instrument procedure in the form shown in Figure I-4-1-1, a reversal procedure, racetrack or holding pattern is required.
3.3 FLIGHT PROCEDURES FOR RACETRACK AND REVERSAL PROCEDURES 3.3.1 Entry
3.3.1.1 Unless the procedure specifies particular entry restrictions, reversal procedures shall be entered from a track within ±30° of the outbound track of the reversal procedure. However, for base turns, where the ±30° direct entry sector does not include the reciprocal of the inbound track, the entry sector is expanded to include it.
By flying the holding you already overflow the IAF. How you position yourself for the Initial Approach Segment doesn't matter as long as you don't descend before established. I would say ATC would expect that you establish yourself in the shortest possible way though, hence the left turn.
By the way:
Chapter 3 INITIAL APPROACH SEGMENT
3.1 GENERAL
3.1.1 Purpose
3.1.1.1 The initial approach segment begins at the initial approach fix (IAF) and ends at the intermediate fix (IF). In the initial approach, the aircraft has left the en-route structure and is manoeuvring to enter the intermediate approach segment.
Corresponds pretty good to the approach in question. Only thing we want to accomplish is to get safe to the IF before the beginning of the Intermediate Approach segment (the segment that is constructed for us to slow down and lining us up for an intercept for the final approach.
To do this maneuver as required and descend when established.