As long as it's projected in 4K, it will look better than the Blu-ray. It's not like you're going to the theater and seeing a 1080p Blu-ray projected. I agree it should not be called new, maybe latest 4K DCP.
I wonder if they've upgraded to a 4K projector. A couple years ago, they advertised that they were showing a 4K DCP of "Dr. Strangelove" but when I asked at the theater, I was told that while the DCP was in 4K, the projector itself was only 2K.
I generally won't pay to see a DCP if I have a Blu-ray at home based on the same source. The difference between the two usually doesn't wow me, of course it's worth keeping in mind that when I say that, we're talking about the jump from a large TV/large home screen going to a very very small theatrical screen, as most of the NYC repertory screenings are on very small screens. I felt burned by that the last couple times I did it... I saw a screening of the original Japanese "Godzilla" on a screen that was actually smaller than the one I have at home, and "Raiders of the Lost Ark" and "Donnie Darko" on one that was only slightly larger. I mean, if it's a choice between "Raiders" at home or on the IMAX screen, that's worth going out for, but to see the same master on a screen that's the same as what I have at home or only slightly larger, that's not really worth it to me, especially factoring in that it's free to watch at home and $15 a ticket to go out.
For a 35mm print, even on the same small screens, I'll come out and see something I have at home on Blu-ray. I know that might be a silly distinction to some but if the print is in good condition, to me that's usually an improvement over the Blu-ray. This next one isn't the best example of a pristine Blu-ray, but a couple months ago I got to see a 35mm print of "Star Trek IV: The Voyage Home" and even with a little bit of fade and some scratches, I found it to be a more enjoyable experience than the Blu-ray.