Is FeatureUpgrading supposed to use the latest Property values?

The 1.0.0.0 version of my Feature's Template.xml file looked like this:

<?xml version="1.0" encoding="utf-8" ?>
<Feature xmlns="http://schemas.microsoft.com/sharepoint/">
  <Properties>
    <Property Key="AvailableWebTemplates" Value="MPS#0;MPS#1;MPS#2;MPS#3;MPS#4" />
  </Properties>
</Feature>

The new version 1.1.0.0 is as follows:

<?xml version="1.0" encoding="utf-8" ?>
<Feature xmlns="http://schemas.microsoft.com/sharepoint/">
 <UpgradeActions>
  <VersionRange BeginVersion="1.0.0.0" EndVersion="1.1.0.0">
   <CustomUpgradeAction Name="UpgradeTo1v1"/>
  </VersionRange>
 </UpgradeActions>
  <Properties>
    <Property Key="AvailableWebTemplates" Value="MPS#0;MPS#1;MPS#2;MPS#3;MPS#4;STS#2" />
  </Properties>
</Feature>

The value of templates is still MPS#0;MPS#1;MPS#2;MPS#3;MPS#4, when the following code runs in FeatureUpgrading:

SPFeatureProperty property = properties.Feature.Properties["AvailableWebTe开发者_C百科mplates"];
string templates = property.Value;

Why am I not getting the updated property value? Is this the way it is supposed to be?

This is indeed the way it is supposed to be: A feature has 1 definition and n instances. The code in FeatureUpgrading is used to upgrade the instances.

The property in your xml updates the feature definition and not the running instances.

properties.Feature.Properties["MyProp"] gets the property value of the running instance properties.Definition.Properties["MyProp"] gets the value of the property in the feature definition.