Is there a difference between non-determinism and a free will choice? The latter seems to be a contradiction. A choice implies a reason which would be a cause, thus determinism.
This test is asking to make random 'choices'. This does have value in something such as sports.
The participant in the test is asked to randomly press either button A or B. The cognitive/mental experience of the participant is the following sequence of operations that seem to happen sequentially in time: 1. The participants is asked which button to push. 2. the participant ponders his decision. 3. the participant pushes the chosen button.
But what this test shows is that while the participants internal monologue is still 'deciding' whether to press A or B in step 2. The software is already able to accurately predict the answer at step 1.
So this indicates that even though your internal monologue might still be going "hmm should I pick A or B?", the decision, where your internal monologue eventually will end up, has already been made.
This is what the clickbait headline refers to; even though it feels like we humans are able to dictate and direct our thoughts, it seems that it doesn't entirely works that way.
There is an older better experiment by Benjamin Libet of this. The participant is directed to choose whether to press a single button, and watching a fast clock display to report the instant the decision is taken. The measurement and comparison of the brain activity clearly shows deciding to press, many milliseconds before the participant experiences deciding. Therefore, the participant does not have free will, is it not so? Since the decision is done before it is known to be done by the subject.
The retort is simple. The leap to "no free will" ignores that consciousness itself is a processing: the brain component that reconciles the internal input and renders it for externality takes time to do its work. The decision is still made by the participant. The subjective experience is behind the objective activation simply just as the signal for a television screen must pass through the wire before it is translated for pixels.
The only definitions of free will that work are deterministic ones.
To elaborate on your TV signal analogy, the TV does not get to "choose" what it shows next no matter the technical reason for the awareness of the choice coming later or not. These are physical deterministic processes.
Because it's not a binary thing, the thought process is more complex but we can take our body for example. We all control our body, right? But now you take an average office worker vs profession sportsman and see that one can do way more precise and measured movements.
Thoughts are similar, you take some buddhist monk who recites 5 hour long mantras by memory for dozen of years and their thought control would be on another level. It is just the question of training and developing the skill.
All the test does is show that humans are bad at bookkeeping historical choices and make ones that don't follow patterns. We are wired to make and follow patterns. Machines are much better, but they certainly don't have more/any free will.
The implicit assumption here is that we are not dictating and directing our thoughts just because the outcome of the process of dictating and directing our thoughts may be predictable. This just doesn't follow.
Consider this analogy: a computer program dictates and directs the state of computer memory, but if I'm able to semi-reliably predict the state of computer memory at any point, then that disproves that the computer program dictates and directs the state of computer memory.
Of course that argument is obviously nonsense, no such test can disprove the fact that the program literally dictates and directs the state of computer memory. I also claim by analogy that no such test can disprove that the process of deliberation that we view as free will actually happens, even if that deliberation is deterministic. Determinism and free will are compatible (see Compatibilism).
So many technical (read: narrowly educated) people make philosophical arguments that just boil down to an incredulous stance.