Using the high/low day feature to give yourself higher calories on training days and lower calories on rest days can be advantageous in that you’ll have more fuel to work hard when you need it. Having more energy on training days may translate into more calories burned, as well as greater increases in strength and muscle mass over time.
However, you don’t need to eat less on non-workout days unless you choose to do so. High and low days are optional based on personal preference. You can eat the same macros every day and still achieve your goal if you’re compliant.