I stopped reporting the AM stations that had dropped IBOC, as it seems that it alerted iBiquity that they were off, and seemed to show up offering help to get them back on the air. In Detroit Metro, all the stations except WJR are still using it, 7 are still using it, and some are low power and the detectable HD signal only gets out a few miles, and the number of receivers have stagnated at best. They blot out several adjacent channel stations from adjacent markets that were previously receivable. At least 5 Daytime signals have been lost to this. The Skywave IBOC has made several PSSAs and even stations on first adjacents useless. Canada has reportedly looked the other way when their stations continue to operate with Day facilities at Night, higher power and less directional DAs, or nondirectional, and are noticeably interfering with cochannels.
Remember that the people who post here are radio geeks, and have better FM radios than the rest of the populace, so we may be underestimating the 400 kHz adjacent channel problems.