The 2019 sage advice compendium has released, and it includes a change to what is considered "official rulings."
Previously, Jeremy Crawford had the capacity to make official rulings over twitter. This is no longer the case. As stated in the updated compendium:
Official rulings on how to interpret rules are made here in the Sage Advice Compendium by the game’s lead rules designer, Jeremy Crawford (@JeremyECrawford on Twitter). The public statements of the D&D team, or anyone else at Wizards of the Coast, are not official rulings; they are advice. Jeremy Crawford’s tweets are often a preview of rulings that will appear here.
Commonly Jeremy's tweets were used in answers as official support when no other material was available. I myself reference him frequently when his input was relevant.
With that being said, how should we handle answers which are now supported by unofficial material due to this change?