This inference is based on certain verses of the Quran:

Firstly, it is the incident of creation of Adam (sws) in which Angels questioned God for His scheme of things which shows they have a conscious existence and ability to raise questions.

Secondly, it is the incident of Prostration to Adam (sws) where both Angels and Jinns were put through a test. Had Angels not been given freewill (irada-o-ikhtayar), then there was no point in taking such a test.

Thirdly, the following verses also tell us that they do have ability of defiance but they do not do it and obey Allah and fear Him in all matters.

وَالْمَلآئِكَةُ وَهُمْ لاَ يَسْتَكْبِرُونَ يَخَافُونَ رَبَّهُم مِّن فَوْقِهِمْ وَيَفْعَلُونَ مَا يُؤْمَرُونَ (١٦: ٤٩-٥٠)

And they are not defiant to the slightest and fear their Lord, who is above them and do exactly as they are bidden. (16:49-50)

قَالُوا اتَّخَذَ الرَّحْمَنُ وَلَدًا سُبْحَانَهُ بَلْ عِبَادٌ مُّكْرَمُونَ لَا يَسْبِقُونَهُ بِالْقَوْلِ وَهُم بِأَمْرِهِ يَعْمَلُونَ يَعْلَمُ مَا بَيْنَ أَيْدِيهِمْ وَمَا خَلْفَهُمْ وَلَا يَشْفَعُونَ إِلَّا لِمَنِ ارْتَضَى وَهُم مِّنْ خَشْيَتِهِ مُشْفِقُونَ وَمَن يَقُلْ مِنْهُمْ إِنِّي إِلَهٌ مِّن دُونِهِ فَذَلِكَ نَجْزِيهِ جَهَنَّمَ كَذَلِكَ نَجْزِي الظَّالِمِينَ (٢١: ٢٦-٢٩)

They say: “The Merciful has children.” [Certainly not] He is above this! In fact [these angels] are but His honoured servants. They never take the initiative in speaking to Him and in all circumstances obey His command. He knows everything what is before them and in front of them and do not intercede for anyone save those whom He accepts, and tremble in awe of Him. And whoever of them says: “I am also a god besides God,” We shall punish Him with Hell. Thus do We reward the wrongdoers. (21:26-29)

عَلَيْهَا مَلَائِكَةٌ غِلَاظٌ شِدَادٌ لَا يَعْصُونَ اللَّهَ مَا أَمَرَهُمْ وَيَفْعَلُونَ مَا يُؤْمَرُونَ (٦:٦٦)

It [–Hell–] will be in the charge of stern and mighty angels shall who never disobey what God commands them and shall do exactly as they are directed. (66:6)

For comments of Ghamidi Sahab, please refer to the video below from 1:28:07 to 1:30:18 and from 1:52:09 to 1:56:23

https://youtu.be/p_MXao4S1NA?t=5287

Please also refer to the video below from 29:39 to 31:12

https://youtu.be/lDfS0ttbT5I?t=1779

https://youtu.be/xTSyqK3uWnI?si=8VTpPu6Z0cFL7Occ