Account Linkage via Match Rule No Longer Available?

I have a use case for leveraging a Match Rule based Account Linkage strategy (for a certain period of time) before transitioning to system-level linkage. However, the option does not appear to be present in the Handler Set anymore. I've checked some instances and have only found one that has this option (it was already configured). Was it removed or am I missing a step? My Match Rule is between Contacts and Companies.

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