-"'meaningful coincidences.'"
-Well that is observer depended term. We as observers "connect" connect different events in a narrative and as thinking agents we project purpose and intention on blind physical processes.
Teleology needs to be demonstrated, not assumed. This assumption is a pseudo philosophical approach on explaining natural events.
So "synchronicity" as an abstract concept has value as a narrative and what it means for our existence. ITs an observer relative term not an intrinsic feature of the phenomenon it describes.
Now the experiences that you are referring to (thinking a person and receiving a phone from him) are known weaknesses in our reasoning. Pattern recognition in animals (and humans) is a very strong urge and bias. We tend to identify the hits and completely ignore the misses. The numerous times we have thought of people and the phone didn't ring just don't register. When a coincidence occurs we tent do see "agency" and purpose behind it.
Richard Feynman used to go up to people all the time and he'd say "You won't believe what happened to me today... you won't believe what happened to me" and people would say "What?" and he'd say "Absolutely nothing". How is it possible in such a huge universe where weird and inexplicable coincidences happen every second, to happen nothing to me?
I will agree with Jung's statement that the connections we make are the result of our practice to project our meanings, I will ignore Chopra's intellectual artifacts since his philosophy isn't based on Naturalistic principles,its are unfalsifiable and indistinguishable for blind synchronization(unparsimonious) and I will address the introduction of a quantum phenomenon in the classical scale (uncertainty principle of Heisenberg).
-"Within physics there is the notion of the uncertainty principle of Heisenberg, which makes causality more complex than we realise. "
-That is a factually wrong statements. First of all this principle doesn't apply to "Physics", but a specific sub-field of quantum physics.
This, again is not an intrinsic feature of causality in nature but as the original German word suggests we are unable to take sharp values from our measurments. Its more like "We are uncertain of the definition our measurements provide" than "we are sure the nature of the quantum world is uncertain".
After all QM is the only framework that can offer predictions up to 99,99(up to 14decimal places) accurate!
So causality is not under threat in the quantum scale and we should point out that Classical and quantum world don't have that much similarities. Energetically and structurally they differ in a huge degree. So its not right to generalize our findings to both scales
Now conceptual artifacts like the notion of karma or any other spiritual construction have their roots on our inability to register all the miss/ lose events during large periods.
Consciousness is the quality of a specific brain state that enable us to be aware of events and the world. Consciousness alone as a mind property is useless if your Central Lateral Thalamus can connected the other brain areas responsible for symbolic language, pattern recognition, reasoning, memory etc and introduce content (thoughts) in our conscious states.
So all those patterns we identify in nature is based on what we are aware, how we reason, what we remember and what we ignore.
The role of consciousness stops with our ability to be conscious of an even, how we reasoning it and what is the produced thought...consciousness is an "observer."