The concept of Al-Qaza that you’re referring to is deduced from hadith narrations like the following:
حَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، حَدَّثَنَا مَعْمَرٌ، عَنْ أَيُّوبَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم رَأَى صَبِيًّا قَدْ حُلِقَ بَعْضُ شَعْرِهِ وَتُرِكَ بَعْضُهُ فَنَهَاهُمْ عَنْ ذَلِكَ وَقَالَ “ احْلِقُوهُ كُلَّهُ أَوِ اتْرُكُوهُ كُلَّهُ ” .
Narrated Abdullah ibn Umar:
The Prophet (ﷺ) saw a boy with part of his head shaved and part left unshaven. He forbade them to do that, saying: Shave it all or leave it all.
Sunan Abi Dawud 4195
Such narrations are about forbidding a pagan practice where people used to shave certain parts of head as an offering to their deities. This has nothing to do with hairstyles but the prohibition of a polytheistic practice.
As a principle, Islam’s intervention in such matters is always from the aspect of morality or polytheism. As long as these two aspects are not of any concern, people are free to make any hairstyles.