The increase from 194.1 to 211.7 electrical degrees for WBBM only accounts for a reduction to about 44 kW. The Night reduction to 42 kW was due to moving closer to other stations on 780 (and possibly 790 and 770). Yes, a small move has that effect. Even coordinate correction often results in slight calculated differences, de minimus as the lawyers would say. Most likely increases would be toward closer and well protected Class Bs like KKOH 780. The 35 kW Day is due to first adjacent stations on 770 and 790. WSGW is an interesting case. It was set up to not overlap 0.5 to 0.5 mV/m. When they changed to 0.5 to 0.25 mV/m overlap, the FCC created overlap, which can't be increased, only decreased, as it did when WBBM moved further away.
They might be able to do conductivity studies to reduce the actual overlap. Years ago, I called the engineer at WMAQ 670, asking about their AUX, which was weaker than WAIT 820 in Genesee County when WMAQ was operating on AUX, so I assumed it was 5 kW to be weaker than WAIT 820 in my direction from Elmhurst. The engineer was very brusk with me, telling me that no way was the AUX 5 kW, it was 10 kW. I asked if there might be lower conductivity near the WMAQ site to explain it, and he said they actually measured 20 mS/m around there. He said they were trying to challenge the grant for WMIC 660 Sandusky, MI and forced it to be more directional, since WNNNNNNBC 660 was unhappy about the cochannel grant, but there was nothing more they could do about it.