So it would seem. Do you know if there are any other class A (I) stations that
protect adjacent channel class B (II) stations in this way?


Other Class II-Bs that receive protection from Class I-Bs include WLAC
protecting Boston's 1510.

Other Class I-Bs that now protect other Class I-As or Class I-Bs include
WSAI/1530, protecting Buffalo's 1520 (first adjacent) and Bahama's 1540 (also
first adjacent). (KXEL/1540, a Class I-B, also protects the Bahamas, and has
from the git-go, even though the Bahama Class I-A operated with 5 kW, later 10
kW, and now 50 kW ... when moving to 50 kW, as required by "Rio", the Bahama
Class I-A installed a DA to protect KXEL, and perhaps the Class II-B in Albany,
NY).

KYW's DA-1 pattern appears to be similar to WRVA's DA-1 pattern, but it it not.

WRVA's is a side-fire, and is symmetrical in two axes.

KYW's is an end-fire and is symmetrical in only one axis.

The nulls towards 1050 are filled by a little. They could be made equal to zero
by a minor parameter change.

The minima towards Mexico is a characteristic of the wide spacing of the
towers, and is not controllable except by reducing or increasing the spacing
between the towers.

The fundamental point here is that KYW's groundwave is protecting the
groundwave of a station of lower class, located somewhat less than 100 miles
away from it.

If KYW were to change its pattern to loosen it up towards 1050, it would be
interfering with a station which was authorized by an international treaty.

Usually, international treaties trump national regulations.