Some Jewish women were kicked out of an Uber after their Palestinian driver found out they were coming from an Israel Independence Day celebration. Uber has since terminated the driver and insisted they don't tolerate "any form of discrimination."
I doubt this will become anyone's cause celebre. That's mostly because taxis (or their replacements) are an arena where norms about serving as a common carrier -- which include broad non-discrimination requirements, far beyond what we think of normally by "non-discrimination" -- are at their strongest. There are excellent reasons why we have pretty sweeping requirements on airlines, taxis, buses, and so on that they can't pick and choose the customers they serve.
But one can certainly imagine how the case for the driver would go. The "speech" argument is already pretty familiar -- after all, he didn't object to "Jews", he objected to "people leaving an Israel Independence day celebration", which is not the same thing. Resurrect some gilded-age 19th century principles about free labor -- where the cab driver and the customer are just free contractors, both responsible for their own affairs and capable of entering into or cancelling a relationship at will -- and suddenly it sounds downright illiberal to "force" the Uber driver to transport customers when his conscience demands otherwise.
And remember: we have a judiciary that is probably more sympathetic to that outlook than at any point in the last century or so. These arguments are not as outlandish as one might think. The "New Lochnerism" already uses free speech as a wedge against huge swaths of the regulatory structure. And much of contemporary labor law -- discrimination or otherwise -- in particular involves not viewing employment as simply the atomistic interaction of free contractors who are at equal liberty to do or not do as they please. Pull that thread, and more might unravel than one intends.