Sorry, November was crazy for me, so I'm coming late to the thread, but thought I'd add what I've seen.
At one time SABs did not show in MM unless searched. In other words, they existed just like they do in Maps; you wouldn't find it while scrolling around the map doing cleanup but would find it if you searched for a category or company name. Once in a blue moon there would be one that was messed up and showed in MM even though it was properly set up in Places.
SABs started to sometimes not send the fact that the address was hidden over to MM a few months back. The solution that Places support seems to have come up with was to go into the MM entry and blank the street address. This then makes them even more violation, typical of Places support who use MM but don't bother to learn the guidelines so they can keep Places users in compliance.
It does seem like they are all showing now. However, don't forget that while anyone can mark a POI for deletion, nothing happens unless trusted reviewers approve. Even with the RER program, most trusted reviews are done by Google Reviewers that have full visibility to the state of the item. Reviewers tend to be extra cautious about deletions; and so the approvals are only likely to happen once the reviewer is well satisfied about the non-compliance. I personally check any that I am deleting or reviewing in Places.
Will some get accidentally deleted? Of course, every process has mistakes happen. The mistakes in this case are almost all caused by Places/G+ issues such as:
- Places isn't hiding the address on the Maps database anymore, causing this issue in the first place.
- It has been months since Places switched to G+ Local and the "Verified/Claimed" marking has yet to reappear, making it hard to judge if a listing is in compliance.
- Places Support just messes things up more via Map Maker misuse.
What you have to remember is that SABs are not allowed on the map; but Places decided to allow them into their system via a method that kept them off the map but appearing in searches. Places is then messing up and putting them on the map, so you cannot blame Map Maker users for deleting them. I'd estimate that almost all of the SABs that appear on the map and get deleted are either not claimed to begin with, and then of those that are claimed most are not in compliance. Those that are in compliance but mistakenly show on the map are a very small minority of the total, and reviewers should catch them but won't always. The map would fill up with useless information if all of those invalid listings weren't deleted; and so the process must continue. Places needs to get it's act in order if it wants to allow a method for SABs to list.
For those of you that spend a lot of time in the Places forum; think about the hundreds of SABs that have come in saying they were deleted. I have yet to see one where it turned out they were in compliance but a Map Maker user deleted them. Leaving out the few that just got in compliance and were deleted by the quality team using old lists; every one of them in the end admits that they never hid it or decided to unhide it.