I'd be interested to know if a plan submitted for review under IRC has ever shown this arrangement - only means of egress through a bedroom - or if the arrangement resulting from use of the intervening room being used as a bedroom.
I'm not sure I actually support to the UPMC requirement, as it would seem to discriminate against some minorities but regardless, it would seem possibly a result of the greater attention paid to IRC versus IPMC by, among others, home builders and designers. Ultimately for IRC it will come down to labels on a drawing, easy to solve by changing the label. The IPMC is more a judgement of how it's being used, not a plan label, and would require rearranging furniture to fix. I'm not trying to be cynical but cite the occupants for this and they move the bed in the intervening room into the more distant room, and are in compliance. How often are you going to check to see that they have remained in compliance?
Does IPMC define bedroom? Is a room with a sofa bed a bedroom? It just feels on thin ice to try to regulate where someone can sleep in their own dwelling.