It wouldn't necessarily if you used a tap in a hole of the correct size for that tap.
If you use a tap in a hole that is intended to be threaded with a thread- forming bolt, it may well be sub-optimal. The required sizes are likely to be different; the larger the thread size, the more significant this may be. You would need to look in engineering handbooks and manufacturers catalogues if you want to be certain.
Also, the way the thread is formed will give different pull-out values.
Back in the real world (of car seat belt mountings at least), that's exactly what I would do.
Chris