Update 7/7/20: Unfortunately it looks like this is no longer working. Seems it stopped for purchases starting 7/5 or 7/6 (probably stopped earning sometime on 7/5). Usually Chase does not claw back like American Express, but that remains to be seen as this was never supposed to earn 5x.
Original post: Reports on Reddit indicate that the Restaurant category and food delivery services are now earning 5x on the Chase Sapphire Reserve card and 3x on the Sapphire Preferred. Apparently, as part of the new 5x gas category for July through September, restaurants got thrown in too, in place of the standard 3x earn.
The Sapphire Preferred card is also earning 3x instead of the ordinary 2x. Unclear if there are spend limits to this unofficial category on these two Sapphire cards.
I was a bit unsure whether to post this, but once it’s on Reddit and other sites I suppose it doesn’t matter much. Another positive aspect is that Chase – from my recollection – has not clawed things back in the past; that’s more an Amex thing. So I can see someone running with this for as long as it works and hoping for the best. Just be sure to always check before making a charge that it’s still working – we’ll update if it dies.