Not the UK Government - till now at any rate!
Zoos (save the Wildfowl Trust) were treated as 'indoor leisure' for nine months. We can only hope that this legally formalised about-face of opinion in the form of an SI, will at least provide some sort of precedent, and when we come out of the third full lockdown (in say March?, or later..) then Zoos will be able to open sooner than last June.
It is evident that Covid spikes have not occurred here as a result of open-air activities being allowed, or happening illegally. The mass crowds at National Trust properties, at Brighton beach, the race riots in London and indeed at some zoos which did not voluntarily restrict foot-fall, did not result in spikes of Covid cases; these happened first time after Government allowed air-travel, schools and universities to re-open (all indoors), and secondly after the country opened up again on December 2nd to go Christmas shopping.