The ToF sensor (or time of flight sensor) won't be making a comeback on the Galaxy S21 next year.
Samsung abandoned it for the Galaxy Note 20 series, and it looks like it won't be available on the Galaxy S21 either. According to a report out of South Korea.
But, Samsung has not completely abandoned the technology. It simply does not have enough use-cases for ToF yet, and the technology it is using isn't as robust as what Apple has.
Apple and Sony have exclusively reserved all of the "direct ToF" technology, which is why Samsung phones and others are using "indirect ToF" which is not as powerful. So due to those technical limitations, Samsung is opting not to use it for now.
ToF will make a comeback though
Samsung is only abandoning ToF for now, it is still working on developing new ToF technologies.
According to some industry insiders, Samsung hasn't given up on the concept. And Samsung's System LSI Division is reportedly working on an image sensor that would be able to greatly improve the capabilities of indirect ToF technology. But that doesn't necessarily mean that it would be used in a consumer product. As that will depend on a few different factors.
Whether Samsung will rejoin the ToF arena and add it in future smartphones, will depend on the technological advancements that would be made by Samsung or another company, in the area.
Additionally, Samsung has decided to watch the evolution of ToF sensors from the sidelines. That's not what Samsung normally does – that's an Apple move, normally. Since Apple has a deal with Sony for exclusivity on the direct ToF sensors, Samsung is going to have to sit on the sidelines and see what Apple does with it in the iPhone and how consumers react to it.
Then, Samsung might reveal it's own solution, depending on how the cards are laid out.
Of course, that still doesn't mean that Samsung's improved ToF sensor will be ready for the Galaxy S21. Keep in mind that the Galaxy S21 is pretty much finished at this point. Samsung is likely doing some final testing on the device in the next couple of months and then will move to mass production by the beginning of the year.
At the earliest, we could see a new ToF sensor from Samsung appear in the Galaxy Note 21 next fall. But I wouldn't hold my breathe for that.