From what I've seen, breaching the policy doesn't disable the ads. Instead it sends the minimum bids sky high. So it's possible that those ads have a high min cpc, but an even higher bid price.

I noticed this recently and spoke to Google about it - they said they are slowly working their way through checking display URL's. I informed them of the advertiser not adhering to their policy and a few days later the ad had been removed.

The april first thing was only for new ads. The way it was supposed to work was that any new ads created that had mismatched display and destination TLD's would require manual review before showing. Have not heard anything official on old ads.

I see this part of AdWords as improved over the time. There has been so much junk that has accumulated over the years out there.
Since invalid display URL is a concept of how those guys are doing their business, as long as Google AdWords team enforces their rule so multiple offenders get punished hard, that’ll do it.

From pure technical perspective, it looks like the system is catching those on the fly, but maybe not all of them. Recently I got two ads disabled even they had good URLs with no question. The only reason I could think about was triple redirect. It’s also possible that at the exact moment of when AdWords checked, some of these URLs did not work properly.

In overall, I think we are in much better position now, and that Google’s response to our submissions will be better.

Compared to couple of months ago, I am positive about the whole thing.

The april first thing was only for new ads.

Well I never figured that it was only for new ads. But anyway what I am noticing these days is that these ads were not present from before the 1st of April. They have only started later. And it is the same main domain that all the ads are landing on.

Also I am surprised that this is taking so long to implement. I would assume that this would be relatively easily automated and since nearly everything at Google is automated, I can't figure why this is taking so long.

I can't figure why this is taking so long

I was of same thinking as you for long time, but it may simply be that it was a very hard thing to implement, indeed.

Skeptics and Google’s critics will probably say that more of invalid display URLs in the game meant more money for Google, and that stands, too.

Hy,
I have seen some adds for, let's say, "widgets" and the display url was
www.website.com/widget.html (this page doesn't exist) and the landing page was www.website.com/black-widget.html (this page exists).
I think the purpose of using the non-existent page as display url was to improve the quality score.

Do you think it's ok? Do you think it really improves the qs?

Thanks