Three thoughts. 1) Sometimes, when leaves are emerging and it turns cold/wet, the leaf stalls (stops opening) and water gets into the furled leaf where it sets the stage for a fungal infection. I have some maples and a couple of apples in pots that were affected thus this year. 2) There is a short period that occurs just after leaves of most trees start to open when they are very fragile (like tissue paper) and easily damaged by wind, which causes something akin to bruising (in humans) and would be consistent with your images. 3) Media which are saturated or compacted are poorly oxygenated. Poor oxygenation seriously limits uptake of Ca, which must be in the nutrient stream at all times if plant cells are to form normally. Low Ca availability affects the integrity of cell walls, which often rupture if an inadequate supply of Ca was not available as the cells formed (think blossom end rot). This physiological disorder very often presents as cracks, tears, holes, and necrotic spots in leaves and fruits where applicable.
No way to tell with any degree of certainty what it is with what there is to work with, but it's not likely something you need to be overly concerned about. I agree you should keep an eye on the new foliage, which will tell you whether you need to explore steps toward remediation.
Al
