A curious incident at an airport that is designed to cause confusion. When determining hot spots, the majority of the airport would be included. Add any poor visibility, fogged windows, snow on ground, standing water etc and it is not a great place to not have a chart showing your location on it.
If ICAO, there would have been a need to note as an amended instruction, can't see that under the FAA 7110 orders or FARAIM.
An alternate viewpoint is that the air side of KDCA was designed for a different era, a different mission, and a different capacity. The ground side has been wonderfully modernized and expanded, which has unfortunately exacerbated the capacity problems of the air side. Like KSFO, KDCA is stuck on a water-locked parcel of land with no room for expansion or reconfiguration of the air side. Other than a slightly lengthened main runway and some EMAS, the air side looks much as it did 60 years ago.
Regarding your ICAO comment, for a note to be added as an amended instruction, the person amending the instruction would have to first realize that they’re issuing an amended instruction. In this incident, I think the ground controller forgot where the E75L was headed and lumped it in with the rest of the stampede heading for runway 1. In his mind, his “cross 4 at J” instruction was just a continuation of previous taxi instructions rather than an amendment.
KDCA has to be one of the top (bottom?) U.S. airports for comms at a blistering pace during crunch time. There is just no dead air time. Poor United 2003 (RTO A319) had to call 3 times for push and another 3 times for taxi.