Don't seem to be any plans for it either in the near future but my hope is that this is mainly due to the pandemic and that developments in London with regards to its more or less disused yet fairly emblematic buildings (Casson, Mappins, Aquarium, the roundhouse near the otters) will resume once repercussions from the pandemic have ceased to affect the zoo financially. They're also dealing with the opening of Monkey Valley in a week or two's time so I reckon the Aquarium and a few associated areas might be next on their hit-list so to speak.
@StoppableSan Don't believe the aquarium is listed...
However I'm afraid you may be right given the decorative painting and the fact that the doors have been plastered over - I don't like to be so cynical but I'm not sure the zoo will undergo much progress in the next decade or so given they are really quite profitable as they are despite fairly large areas of the zoo in disrepair.
