Lots of folks have different ideas and preferences about this sort of thing.
They often have different experiences to 'justify' their preferences, or at least explain why they feel a certain way about this subject.
I remember reading a NIJ (National Institute of Justice)
recommendation some years ago that service pistols should be fired for function for 300 rounds before being placed into service. Don't personally know of anyone that follows that recommendation, though.
I like to generally run 150+/- rounds through any high quality 'stock' service pistol, produced by one of the major manufacturers who do a lot of LE business, to give it a 'shake down'. Sometimes less, sometimes more. I like getting to know a pistol during this time.
Just from the perspective of checking magazine function I often like to run a box (50/ct) of rounds through each magazine, if possible. Again, sometimes more, and sometimes less. Depends.
Some pistols, especially those of 'tighter tolerances', may benefit from the 'working surfaces' becoming worn together during the first few hundred rounds; burred edges discovered; any damaged or out-of-spec parts discovered; the need for sight adjustments discovered (although I've often found that it's more often the shooter who requires some 'adjustment', rather than the sights, but sometimes sights certainly may require an adjustment
); sometimes recoil and magazine springs may become 'better suited' to the 'needs' of some shooters after the pistol has been fired a couple or so hundred rounds; some pistols may exhibit a 'preference' or 'dislike' for some ammunition which is discovered during initial familiarization/break-in, etc., etc..
It's may also be fair to say that sometimes some infrequent 'things' which may happen during the first couple of hundred rounds, may not happen again ... after the pistol has been 'broken in', so to speak.
Bottom line? Dunno. Depends.
I have discovered conditions involving parts manifest themselves during the first couple of hundred rounds fired through a new pistol which required parts replacement, though, so you never know.
Sometimes a 'problem' which occurs during the first magazine load may truly be a PROBLEM which requires immediate correction or repair ... and then again some things may just be an unfortunate hiccup while the factory sharp edges are becoming mated to themselves. When in doubt, ask the factory warranty/repair technicians, or a licensed gunsmith authorized to perform warranty repair for the manufacturer.
Hey, I watched a P226 & P220 EACH exhibit single feeding failures during their first magazine loads, in the hands of two different firearms instructors, using standard service ammunition, right out of the box.
They both did fine afterward, FWIW, during additional testing and evaluation.
Things happen sometimes ...
Best to catch it on the static range, I'd think ...