No. A shared frequency reference can align long-term frequency, but it does not by itself guarantee deterministic or repeatable relative RF phase. Divider state, PLL acquisition, trigger latency, cable electrical length, distribution delay and channel calibration can all change phase while every source remains frequency locked.
Define the required behavior: bounded drift during one dwell, deterministic phase after a common trigger, repeatability after retune, coherence after relock, or recovery after power cycle. State carrier, channel spacing, reference and trigger distribution, cable states, temperature, observation time and allowable phase error.
Reject a coherence claim demonstrated only once after manual phase alignment. Acceptance must repeat the sequence across channels, tuning states and restarts, record relative phase versus time, and show how calibration and delay compensation are applied. If only common frequency is needed, say so and avoid paying for a stronger phase-repeatability requirement.