That’s my assessment as well. The division between micro and macro appears to be as subjective as the division between genera, families, and orders in taxonomy. Humans tend to have this psychological need to put things into black and white categories, even in cases when there is a obvious spectrum of white to gray to black.
As emphasized in earlier posts, there isn’t a one sentence definition that is ever going to completely describe evolution, be it micro or macro. However, we can still use definitions that explain most of it.
The definition you are using (change in alleles) is trying to convey the idea of mutations spreading through populations. This is the basic mechanism that adds up to macroevolution.
A good analogy might be how humans grow up and age. There is no obvious point where we stop being a child and become an adult. There is no single point where we go from being young to old, short to tall, or skinny to fat. It could also be said that growth and aging are not linear. When we go through puberty there are changes that happen quite quickly, and it is followed much slower changes in our bodies. We microgrow each day, and it accumulates into macrogrowth and macrochange over our lifetimes. That seems to be very similar to how evolution works.