Short answer: yes.
You might be concerned about this in case you are trying to keep track of spammy links for the purposes of negative SEO.
If a spammy domain goes down, then it will start showing error messages in MB like SD (server down) and BNF (backlink not found).
In that case you might want to delete the link since it no longer exists.
You might wonder whether deleting the link will still let you be alerted if the spammy link/domain comes back to life and starts linking to you again.
You can rest assured that in that case, we will rediscover the links from that domain, and they will show up in your Monitor Backlinks account again.