A lot of the avionics installation are being soldered connections as noted in the video I posted.
Just to throw out an instance I was involved with regarding a pair of Garmin G5's that I installed. I wired two wires into a single pin which is the way it is recommended from the Garmin GNS-430 days. The avionics shop removed that pin and soldered the two wires into a single lead and then installed it onto the the single pin and reinstalled it.
Soldering on aircraft has been around a long time and a Navy Avionics guy said they solder everything.
Like all things, there is a place and time. The capacitor on the alternator is soldered and usually break unless we support the wire by typing the wire to the capacitor to prevent vibration.
The solder joint can make for a better connection electrically and with some of the new connectors that are installed properly can be strong mechanically. If you go back your to video and look at the yellow wire being soldered with the solder sleeve, and look close, you will notice that the solder is not fully melted.