Yes...if DMA interrupt mode is set to ENUM_DMA_CFG_XCNT_INT, interrupt occurs when DMA_XCNT becomes zero. But since you are using Auto-buffer mode, eventhough interrupt occurs when X_CNT becomes zero, DMA will not wait for processor to come into ISR...By the time processor comes into ISR, it would have already started for next work-unit.
You can verify this by setting DMA in STOP mode ENUM_DMA_CFG_STOP.