Analysis Services 2012 - Does Alter Partition Update the Header?

Does anyone know if running an Alter statement (XMLA) which modifies the Query Definition on an already processed partition results in an updated partition header?

We are trying to manage processing for several large distinct count measure groups and need to know the partition header is still optimized for read performance following a query definition change. Thanks in advance for any info -- Jeremy

OS: Windows Server 2008 R2, SQL Server 2012

<Alter ObjectExpansion="ExpandFull" xmlns="http://schemas.microsoft.com/analysisservices/2003/engine">
    <Object>
        <Database>TestCubeID</Database></DatabaseID>
        <CubeID>TestCubeID</CubeID>
        <MeasureGroupID>User Count</MeasureGroupID>
        <PartitionID>User Count-1</PartitionID>
    </Object>
    <ObjectDefinition>
        <Partition xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ddl2="http://schemas.microsoft.com/analysisservices/2003/engine/2" xmlns:ddl2_2="http://schemas.microsoft.com/analysisservices/2003/engine/2/2" xmlns:ddl100_100="http://schemas.microsoft.com/analysisservices/2008/engine/100/100" xmlns:ddl200="http://schemas.microsoft.com/analysisservices/2010/engine/200" xmlns:ddl200_200="http://schemas.microsoft.com/analysisservices/2010/engine/200/200" xmlns:ddl300="http://schemas.microsoft.com/analysisservices/2011/engine/300" xmlns:ddl300_300="http://schemas.microsoft.com/analysisservices/2011/engine/300/300">
            <ID>User Count-1</ID>
            <Name>User Count-1</Name>
            <Source xsi:type="QueryBinding">
                <DataSourceID>WHLST</DataSourceID>
                <QueryDefinition> SELECT.... between 18226868 and 19140628</QueryDefinition>
            </Source>
            <StorageMode>Molap</StorageMode>
            <ProcessingMode>Regular</ProcessingMode>
            <ProactiveCaching>
                <SilenceInterval>-PT1S</SilenceInterval>
                <Latency>-PT1S</Latency>
                <SilenceOverrideInterval>-PT1S</SilenceOverrideInterval>
                <ForceRebuildInterval>-PT1S</ForceRebuildInterval>
                <Source xsi:type="ProactiveCachingInheritedBinding" />
            </ProactiveCaching>
            <EstimatedRows>20000000</EstimatedRows>
            <AggregationDesignID>Aggregation1</AggregationDesignID>
        </Partition>
    </ObjectDefinition>
</Alter>