Why no Android 16 AOSP images, but there are Google APIs ones?

Bash script:

for version in 35 36
do
    echo -e "$version\n"
    for flavor in android google_apis google_apis_playstore
    do
        echo $flavor
        URL=https://dl.google.com/android/repository/sys-img/$flavor
        if [ $flavor = 'android' ]
        then
            flavor='default'
        fi
        fileName=`curl -s $URL/sys-img2-4.xml | xmlstarlet sel -t -m "//remotePackage[@path=\"system-images;android-$version;$flavor;x86_64\"]/archives/archive/complete/url" -v . -n`
        echo $fileName
    done
    echo
done

Output:

35

android
x86_64-35_r02.zip
google_apis
x86_64-35_r09.zip
google_apis_playstore
x86_64-35_r09.zip

36

android

google_apis
x86_64-36_r07.zip
google_apis_playstore
x86_64-36_r07.zip

Source: the Stack Overflow answer 57421122