Is it possible to look forward in time to see the Estimated Time assigned to a given user for the next week even if no time has been logged against those tickets yet?
In case of Jira Cloud, you may try Time Tracking report, where you may leave dates unset, and see Estimated Time for all issues matching selected Filter or Project.
It is also possible to add Remaining Estimate in Additional Fields option in Timesheet report. And you may enable Show Empty Rows option in case of Jira Server, or Show Empty Issues option in case of Jira Cloud in report configuration, to see issues with no time logged.
Note, it's not possible to have Timesheet report for dates in future. If you are looking for kind of view of planned work by days, please check Work Plan Report add-on. Note, it's for Jira Server, and not for Jira Cloud, but you may ask for it on support portal.