where did you get those numbers?
The 2017 manual here https://www.mazdausa.com/siteassets/pdf/manuals-and-guides/2017/cx-5/2017-cx-5-owners-manual.pdf
lists 4.8 US Qt for oil+filter replacement for the 2.5
EDIT: nevermind.. I see what you did but I think you are mistaken in thinking that draining the engine for 3 hours somehow results in more than 4.8 US qt. coming out.
We'll just have to agree to disagree(drinks). All I know is that it took almost 5.5 quarts to get to the top of the fill line and the engine holds 5.8 quarts of oil when dry. And I didn't drain on a lift or flat surface, but on ramps, so the engine is angled to drain toward the plug. I know others have mentioned needing more than 5 quarts as well, so this is not new, I don't think. I'll measure next oil change in about 3.5 months.