I, as many people, go to that tab to see a list of any updates that might be available, not any that have already been installed.
The typical use case for an update tab/page/screen is to list available updates, so people are used to going there and only seeing something there if there's something to update, and basically not seeing anything there (aside from maybe some related links, like purchases, etc.) if there are no updates available.
That's how the App Store functioned all the time, and how it functions in other places like OS X, for example. That's how it works in other systems as well--if I check for Windows updates, I get a list of available updates, and not a list of those that have already been installed--there's a separate link to go to those if I want to see those. Fairly established design as far as an updates screen is concerned.
That's also how purchases have implemented--you don't get the latest list of everything on the phone on that updates page, you get a purchases link at the top that is easily accessible from that page, which can be done the same way for recently updated apps.