Backlinks from missing sites

[rickmic]

While combing though spammy backlinks, I'm finding a lot of supposedly "active" links that lead to 404 errors, pages that contain no html, domains for sale, and sites that all have a uniform design which I can't tell if they're  web host default pages, or pages using a spammy third-party link aggregator (or both). 
For example: http://easyreveal.us/

So, do I disavow missing sites? Lost sites? Is there a drawback to disavowing sites that have been removed?

Any help would be appreciated.

[Psnowden]

The only real problem is disavowing a site that might be helping you, but in this case that doesn't seem likely. It's more about a waste of your time and efforts.

[rickmic]

Well, that's a relief.
At the same time, are there any drawbacks in disavowing sites? Beyond the time invested, of course?

[Psnowden]

I would just ignore them (as Google's John Mueller talks about) unless they're WAY over the top and you can see it hurting your SERP.  Google has gotten much better at looking past these links and in most cases the disavow tool is used by blackhat outfits that get caught with a PBN and they need to quickly cut ties.