Hmm I'm not so sure. Two derailments that spring to mind are Ufton Nervet and Grayrigg.
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Ufton Nervet the report made it pretty clear that the shattering of toughend glass contributed to both fatalities and injuries of passengers. It concluded that at least two and possible four of the six fatalities on the train were caused by being ejected through broken windows. Whilst others were injured when limbs became trapped between coaches and the outside, by being cut when thrown against broken windows and by being hit be debris (large quantities of ballast was found inside the coaches). If the windows had been of current standards at the time of the crash which required all but the emergency egress windows to be of laminated glass the number of severity of injures would have been less.
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Grayrigg (where all but the egress windows were laminated) in the leading coach all the windows shattered but only the egress window actually broke (and a passenger was partially ejected through this window). In the second three windows (including the egress) had broken through with one passenger again being ejected through them (as well as ballast/soil entering the train). In the rest of the train many windows were shattered but only a few egress windows broken through. Both of the passengers that had been ejected through windows suffered serious injuries (though it does make it clear that they are unsure in one case if the injuries came from ejection or not). The report cites the strength of the laminted windows as one of the main factors in the 390s impressive crashworthiness (it draws on Ufton Nervet as an example where weak windows significantly contributed to injuries and fatalities).
So to my mind it would take something pretty significant to lead to a change of policy back towards having emergency windows as passengers being ejected from the train has been a serious cause of death and injury in previous accidents. One accident where having smashed windows made a difference for aiding passengers to escape was
Ladbroke Grove where a serious fire broke out in coach H of the HST. However, how many accidents in say the last twenty years have involved a fire bad enough to cause passengers to escape through windows? Then contrast that with how many have been bad enough that breaking windows has caused injury and fatalities (but there has been no fire or only a small one)?