Apparently that's true .. it isn't. A good example is up in Fargo. Two brand new AM stations are getting ready to take to the air - KKAG (740) and WZFN (1100). And the best part is that both are 50,000 watt furnaces with huge signals.
It does seem true...AM is still alive and well

AM would be even stronger if the weaker stations were removed from the band. You know, the ones that serve no useful purpose. Low power, shoehorned directional signals which only simulcast the FM and cause interference to other co-channel or adjacent channel stations.
This is what the expanded band was *supposed* to be about. The idea was to remove the biggest interference-makers and relocate them above 1600Khz. Unfortunately, it now looks like the FCC will allow the "old" allocations to remain active or to be reactivated, if now dark. Witness the resurrection of 1550 in Cassleton. This was KQWB's original frequency, vacated when they moved to 1660. It should stay that way.