Usually the turntable does not, but the pre-amp does. There is this thing called RIAA equlization that's done on phono inputs.
Ceramic cartridges use regular line inputs, I think.
Presumably you're too young to actually remember record players?
There were four types of cartridge - ceramic, crystal, moving coil and moving magnet - moving coil were always extremely rare, and not supported by many preamps or amplifiers. My Trio/Kenwood amp is switchable, not that I've used a record deck for decades, but I've never had (or indeed even seen) a moving coil cartridge.
NONE of them will connect to a line input - ceramic and crystal require a flat input, but of a
MUCH higher impedance - I commonly used a simple 2n3819 FET buffer stage with 2.2Meg input impedance for discos, and they always sounded great. Using too low an impedance, such as a line input or guitar input results in a huge loss of bass. You can plug a ceramic cartridge in to a moving magnet input though, as the RIAA equalisation and much higher gain compensates for the low input impedance somewhat.
You're perfectly correct though that if he's only changing the stylus (
NOT a needle) there's no need to touch any wires.
Assuming he means changing the cartridge?, I changed hundreds and hundreds 'back in the day', they were a very common failure - and very simple to do. Just four wires, with two of them a common earth. Your buzzing technique is fine, as is simply going though the options two by two.
If there's a removable headshell, this makes it
MUCH easier.
One possible issue is weight - if you change to a lighter cartridge you might not be in the adjustment range. We used to have a tin of lead seals (used for electricity meters) and I commonly glued one of those in the headshell if required.