The short answer is that no, they do not mean the same thing.
The first with an inflection of the progressive construction be playing is a simple statement of the evidentiary future, but the second with an inflection of will play is a statement of a future that the speaker insists must come to pass.
Probabilities vs Demands
When someone says:
I will not ...
This is reported speech, where we backshift tenses. Backshifting happens when a verb tense is shifted back to a past form in reported speech.
What was said by John: "I am hungry." In reported speech, we see "John said that he was hungry."
In your example "I told him I wasn’t playing soccer anymore", what was actually said was &...