Just some of my observations.
My new finds seems to be slowing as of late , even though my searching has expanded. It is mainly the odd lesser searched issues that I seem to stumble into.
That and when I sorted them by date (month/year) other than that one outlier Batman Robin Adventures 1997
It seems just a few months have been the ones still hiding.
That said I am still waiting for a main run gap to be closed on a title like Batman,Superman, Wonder Woman , Green Lantern, but other than that one Green Latern 60 it has been awhile since any new of those has shown up, but back to the (month/year) most of the gaps in each title line up . Which suggests that those were not made.
If one of any of those should appear , then it would definitely be interesting as that might suggest that there may have been some made.