Although, the maps are clubbed under the "charts" on the ribbon, and for all intent and purpose are called map charts by Microsoft; they aren't surfaced when using the document webpart in modern pages (after selecting chart and giving the name).
Maps are not (yet) an option. Hope to see this coming.
Not only this, even if a named chart is provided as option setting, the web part shows all named entities i.e all named charts and tables as pages. As soon as you click on the first page which shows the chart set in the options, it changes to the second page. Strange! If a named chart/table is set, then the webpart should show only that and nothing else.
Another problem, with modern team site pages is that the webpart takes full width and a predefined height with no option to restrict that. I hope with new sections in communication sites, this may get solved to some extent.
I really am going to miss the "Excel Web Access" webpart under "Business Data" in the classic mode. We have our project sites with a dashboard like page each loaded with such webparts which show quite a lot EWA webparts each displaying a chart. By carefully using a size in the Excel of the charts, we could have neatly lines tiles of these charts. But yes, even that webpart will also not display a map chart even if that is named. Even then, seriously, classic mode will be missed.
