Is it true that as I add size I should continue to increase my calories to keep from losing the muscle I’ve earned?
Technically yes, but I hear this argument all the time from gym goers who are fat and looking to justify their calorie consumption. The key words in this question are “add” and “size”. You need to identify what the added size will be. More often than not the added size is fat accumulated in the name of “bulking up” after which some gym goers continue to add more calories to maintain that new “size”, thus compounding the problem. Timing your nutrition is infinitely more important than the total number of calories you consume in a day.