The ABS "wheeze" is actuating the ABS pump on the secondary circuit, which is what T4 does but under controlled conditions, both in primary and secondary circuits.
However assuming the ignition is not turned on during the bleed process, the valve block within the ABS pump remains shut, and no air can enter.
It is not that any air will be introduced to the system in any event when a fluid change is taking place unless the fluid level is allowed to drop sufficiently in the master cylinder reservoir.
If you didn't have SPS before you started, and you bleed the system in the correct order, you won't have it once you finish.
Brian
