There is always a lot of misinformation on this topic, which is mainly due to differences between the NEC, manufacturer's directives, and reality.
The NEC typically specifies circuit requirements that are well above the "reality" of woodworking equipment. For that reason, I will Not address NEC ampacity considerations. I don't agree with them, but neither could I advise not following them. Consult with an electrician as to what the local requirements may be.
Manufacturer's directives are typically all over the map, with some manufacturers known for requiring circuits larger than necessary, to others requiring circuits smaller than required. Without looking at a case-by-case basis, this is typically the least reliable information.
What I will say, in this particular case, specifying a maximum circuit size of 20 amps is in contravention with the NEC tables. That's not to say that a 20-amp circuit is insufficient, only that it shouldn't be stated as a maximum.
On the opposite extreme, I have seen some manufacturers specifying minimum circuit ampacities that are well above the NEC tables. Again, that's not to say that having an over-sized circuit is bad, just that it shouldn't be listed as a minimum.
Personally, I prefer to take the approach based on the realities of how woodworking equipment is used in real life. In that regard, human-fed woodworking tools rarely ever see maximum load, and even then, is very short duration. They also experience significant no-load idle-time between cuts and operations.
But conversely, some woodworking tools may experience very frequent re-starts compared to running or idle time. Any tool that experiences frequent restarts without down-time, should be placed on a larger than typical circuit. The high-amperage start current will heat the circuit conductors (and breaker) more than a continuously running machine.
My reality is that I don't want to work with wires that are bigger and stiffer than necessary, yet of sufficient size to never trip a breaker during normal usage. If a 20-amp breaker never trips, then there is not a reason to have used a 30-amp breaker. So I base my circuit size on the motor's nameplate amperage, because I know that the motor will very rarely ever even reach that amperage, let alone exceed it for any length of time.