To "fix" the issue GA could add a layer for the user to select which URL parameters need to be codified in the saved link. Then GA would need to add a layer that included sharing options. Maybe similar to the share object option for dashboards.
There is a workaround I came up with that allows you to both share (or send) a link to the actual report at the current state (including date) and keep up with it in GA. After customizing the report (important: before saving as a custom report) copy the URL. The GA API has built a state reproducible URL for authorized users. You could send this link to whomever and be just be done, but if you want to use GA to document the effort, you can add an annotation there in the report. You need to click the Annotation Drawer dropdown below the explorer.
Pick a date and add add an annotation containing the URL you copied for the report. Because of the character limit (160) you may need to use a URL shortener.
Now feel free to save the report and share the report with the email feature. The share generates a form and has to attach a document of the current state. I choose to go ahead and paste the URL there again. Be sure and send a copy to yourself so you can track the share, otherwise I suppose it goes to the ether.