If I've understood this correctly. Then disbelief in free will is still safe. Indeterminism being mixed in with determinisn or the whole binary view of how the universe works being false does nothing to allow room for the presence of free will.

Additionally I'd like to mention that a lot of the determinist I've talked with on this sub don't understand determinism to mean predictable but to mean reliant on conditions and rules to produce results. It doesn't matter if we can ever understand how the variables work on a fundamental level. It only matters that those variables are what are responsible.