ArcGIS Pro Overwrite Vector and Map Image Services (Map Service). It would be nice to be able to overwrite services that happen to be Vector and Map Image. Currently we can only overwrite Feature Services from ArcGIS Pro.
I believe OP is referring to the ability to overwrite Cached Map Image Web Layer which cannot be overwritten on Pro so long there is an existing Cache on the server. The only option right now is deleting the service reference in portal, then deleting the service itself for (in Server Manager - not stable) or more reliably in ArcCatalog which works better than Server Manager for these sort of managerial tasks. Unfortunately, here we are using "legacy" tech. It's not possible to do all this in Pro?
From ArcGIS Pro, if an update to your vector tile layer is required, we recommend using Replace Web Layer (Replace a web layer—ArcGIS Pro | ArcGIS Desktop). This will replace the content of one vector tile layer with the contents of another vector tile layer with zero downtime.
You are correct in that there is currently no way to update a web imagery layer while maintaining its item ID. This functionality is planned for a future release.
"To update a map image layer on your Enterprise portal (with federated servers), use Overwrite Web Layer (Overwrite a web layer—ArcGIS Pro | ArcGIS Desktop). " which isn't a work around for the majority of users that can't afford the resources to manage a Portal installation, and are using unfederated servers. Don't forget to check out https://community.esri.com/ideas/12258 which is not yet implemented as most of the core functionality, which exists in ArcMap, has not been ported to Pro.
