Of Galaxy Z Fold 2 appeared on the market without S Pen, because the current S Pen is not suitable for this. Still, according to rumors, it will soon be possible to use a stylus, because Samsung would work on a new S Pen that would be suitable for the foldable phones.
Samsung always supplies an S Pen with the Galaxy Note devices so that you can make optimal use of the large screen. The Galaxy Z Fold devices have an even larger screen, but the current technology of the S Pen makes it impossible to apply the S Pen functions to foldable phones. The thin layer of Ultra Thin Glass is also too easy to damage with an S Pen. Nevertheless, we can probably operate the Galaxy Z Fold with a pen in the future, because Samsung would now work on a new S Pen that is also suitable for foldable smartphones.
The current S Pen uses EMR (Electro-magnetic Resonance) technology, where magnetic signals are received by a digitizer, after which the smartphone can determine the position of the S Pen. A digitizer for the EMR technology is still difficult to develop for foldable smartphones, because this material is difficult to bend. That is why Samsung is now working on an S Pen that uses the AES (Active Electrostatic Solution) technology.
The stylus from Apple and Microsoft, among others, use the AES technology. AES technology is more accurate than EMR technology, but the disadvantage of AES is that a battery is required in the stylus.
Finally, Samsung would provide the Galaxy Z Fold 3 with a layer of Ultra Thin Glass that is twice as thick as that of the Z Fold 2. This allows the AMOLED screen of the Z Fold 3 to absorb the power that is carried out with the S Pen. process better.
It is still a rumor for the time being and it is still quite a challenge to make a thicker folding screen. So take this message with a grain of salt.