Just as I agreed with your assessment of Los Angeles Zoo, I agree completely with your assessment of Phoenix Zoo. I have a feeling you and I see eye to eye in many ways on zoos. Since you are now in my state and I am familiar with that zoo (and currently a member), I will make a few observations.
1) Rain in March is unusual and for us in the desert rain at any time is always a blessing. I also think rainy days are the best time to visit a zoo (anywhere, unless it's a severe downpour).
2) Arizona Trails (which does have dreadfully small cat exhibits) actually is quite old, contrary to your hunch. I first visited Arizona in 1992 and it was there then. I am not sure how much earlier it was built. The only major recent change was the paving of the path all the way to Mexican wolves; it used to be a gravel path.
3) Arizona (as of now) only has a few confirmed cases of C19 virus whereas California has a lot, so I think it is good that you moved east from your starting point. The whole situation is bad for everyone - you may have seen that
@lintworm was forced to cancel his trip due to yesterday's presidential proclamation about European visitors. I am a planner too who likes to have everything pre-arranged (one area that my friend
@snowleopard and I have nothing in common). I certainly understand your frustration but as you say, all you can do is make the best of it and carry on and watch how things progress. My advice is to do what you did yesterday - enjoy your zoo visits (and other outings) and temporarily forget there is a pandemic.
4) The only thing I will add about the Africa section is it has the best cheetah exhibit I have seen. You may or may not know, but the neighboring wild dog exhibit (which has the same design) was a second cheetah exhibit for many years.