And if it occurs in the simulator, who give a , as long as you carry out the appropriate actions?
Or is some TRI making a point for his/her own benefit?
On the latter comment, the answer is not in the slightest. On the former comment a reply to that is unnecessary. The reason for the question is that as a simulator instructor about to inflict a dual flameout or Loss of Thrust of Both Engines at high altitude, it behoves a competent instructor to thoroughly brief the students (or candidates) on what to expect and what to look for. Loss of thrust at high altitude is no laughing matter and things can happen rapidly. It is a training exercise - not thrown into the deep end as a test.
Because there will be a steady leaking of cabin air with both engines shut down at high altitude, most pilots under training would like to know whether the leak is like a rapid decompression or whether a lot less urgency. Trying to re-start an engine at high altitude when both have run down, as well as coping with a rising cabin altitude, is a high work load event to say the least. Any allied information that could aid the pilot in the decision making process would therefore surely be helpful. Hence the original question about expected rate of climb of cabin altitude following a double flame-out in a 737.