I think that using date-of-report is better for lay-people. Pro/cons:
- There's a one time spike when the methodology changes
= The data lags reality on the ground (true for both date-of-report and date-of-death)
+ Past dates aren't updated, so there isn't a continuous bias to show a slowdown in the number of new deaths
I think that the last point is the most important because it's super easy for people to misinterpret provisional data. People were talking about covid-19 not causing excess mortality because using date-of-death always shows a dip for the present: https://twitter.com/TylerMorganMe/status/1248452375162925057
You can also see the same thing in the top comment on this Euromomo thread: https://news.ycombinator.com/item?id=22866238
> Another very surprising thing is to see no excess mortality in Sweden, a country criticized for a laxer strategy against COVID-19. I was not expecting to see that.
That was week 14 for https://euromomo.eu/graphs-and-maps/ . In fact, week 14's excess death z-score for Sweden was in the "very high excess" category after the data was collected.