No, she is the leader of the retail division. While she probably had input into what she thought the numbers would be a completely different division determines how many of each type are made. There are too many other factors involved to have Angela make those decisions. There is a limit on how many watches Apple can make within a given time period and It differs with various models of whatever device they are making. She would have no knowledge of how many Sapphire watch crystals of 38 and 42mm can be supplied within a given time period. She has no detailed information on the cost, processes to design, make, etc. I would guess she told them she could sell as many watches as they could supply her by launch day.
Last I saw there were 30 people on the I didn't get my 42mm SS with BSB in this thread. We don't know how many Apple shipped and we don't know how many people are waiting until May 8th, which was the date range they gave when ordering. It may be that 10 times that many didn't get their watch. Which would be 300. Still a pretty close shot.
Given the Sapphire situation and the size I still say the availability of Sapphire crystals was, and is, a limiting factor on the 42mm SS watch.
To put it another way, are you going to fire the retail manager of a store selling game consoles because they couldn't get enough of them to sell to every person on launch day? They have no control how many can be made. Again, would you have been happier if they had moved launch day to May 8th and you got your watch on that day?