Not really.
XenForo will likely always be exclusively MySQL based. That is, it has to be without some incredibly significant changes that we just don’t want to do.
You’ll notice though this is a new type of database adapter. XF won’t actually attempt to run using it. It’s entirely for accessing other databases which may be running other software.
In this particular case it’s because we’re in the process of writing a Discourse importer so we need this adapter during the import process.