We think this is best released to RHOS 8 by packaging python-heatclient-1.0.0. I'll test a scratch build and try it with the latest puddle.

testing..

[stack@instack ~]$ heat stack-delete overcloud
Are you sure you want to delete this stack(s) [y/N]? n
[stack@instack ~]$ heat stack-delete overcloud
Are you sure you want to delete this stack(s) [y/N]? y
+--------------------------------------+------------+-----------------+---------------------+--------------+
| id                                   | stack_name | stack_status    | creation_time       | updated_time |
+--------------------------------------+------------+-----------------+---------------------+--------------+
| aa744b66-c1f1-4a5c-ba64-8a75bf45457a | overcloud  | CREATE_COMPLETE | 2016-03-29T11:10:36 | None         |
+--------------------------------------+------------+-----------------+---------------------+--------------+


The warning could be more prominent IMO, but this should solve the main problem.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHEA-2016-0603.html