What does this mean? (GSC Question)

Hope everyone's off to a good start for the week! Just have a question for y'all. I have a client with over 200 backlinks on Google Search Console showing up, however when I check for indexing in Scrapebox about 2/3 of them are not indexed.

Does this mean they were at some point indexed and then de-indexed? This wouldn't surprise me as many of these are spammy links done by a previous SEO from a few years ago.

Also, when considering the links and ratio of anchor texts, ********/nofollow, etc should I account for the links that arent showing up in google search if they are in search console? How does it work?

Thanks in advance guys. Long time lurker and just started actually posting here and you have all helped me a lot with these questions that I've never been able to find answers for easily. One love

Maybe, but "indexed" is not at all cut and dry, depending on the ip you checked with and the local google data center then it may show indexed or not. Meaning yes its possible for a link to be both indexed and not indexed if you count indexed as just whatever the google data center you happen to connect to says, especially if they are weak spammy links.