RAT 5
Intruder, there is no disagreement with the suggestions of what to say, but it is essential to consider how the decision to say something is reached.
The OP questions the logic required. The conditions and assumptions before the 'logical' IF need to be well-considered and clearly stated before creating a procedure.
The SKYbrary video clip starts with the assumption that a head-up pilot will suffer an illusion, opposed to being head down - inaccurate. The most demanding illusions are those which challenge the belief in the instruments, i.e. suffering an illusion when head down. Instrument displays do not provide immunity, but are the basis of disciplined attention.
The procedure requiring a call assumes that the monitoring pilot is not suffering an illusion, which cannot be assured; as discussed in previous posts.
When the call is given, including pitch direction, who's view in correct. This cannot be established without an independent arbitrating view from someone not suffering an illusion - which cannot be assured.
Thus to mitigate the hazard of illusions we need to understand the circumstances when they could occur and the importance of believing the flight instruments, whatever we might feel.
When assessing the risk of illusion, it is also important to consider the frequency in addition to the potential outcomes. Somatogravic illusions depend on acceleration; in commercial operations the risk during take off might be higher than for a go-around because of greater speed change and rate.
GA procedures may only involve a 10 kt speed change, less than 3 kts/sec, which is much less than the example given elsewhere in SKYbrary. (also applies to deceleration)
A greater threat during GA might be the perception of pitch change based on aircraft pitching moment from thrust and configuration change thus inappropriate crew intervention; then again there is trim....
Each situation requires assessment according to aircraft type and operation; don't assume that someone's else's procedure will work in your operation.