This week we had an issue where we had some differences in the Content Types that where pushed from the Content Type hub. We wanted to make sure all Content Types where updated in the next push. After some digging around on the internet I found that there is a property in the SPWeb.Properties called “MetadataTimeStamp”. This property contains the date of the last sync with this site collection. If you clear the value of this property, the Content Type synchronization Job will update this sitecollection.
I wrote a script to clear this property for every site collection in an web application or for a single site collection.