Hi there. Danny here, co founder at Snyk and the guy behind the zip slip research.
First, at no point we claimed that this is a new type of vulnerability, the contrary, in every talk i gave, most are on youtube, i started with saying that it's a 30yo vuln, originally published in phrack showing the actual phrack issue.
Secondly, the real problem here is that 30 years later, in some languages like Java, more than 90% of archive extraction implementations are vulnerable to this issue, like really vulnerable, RCE kind of vulnerable. so no, this is not just a "zip format gotcha", this is a real issue in real apps. this is the kind of vulnerability that every security person knows of, but not that many developers do. when they write extraction code, they most often do it without considering the path traversal issues.
Some languages solved it by providing a simple api for you to extract an archive, like python's zipfile.extractall(), this is great! but others like java stayed behind and made the developers either write it themselves (wrongly) or copy and paste it from stackoverflow (most answers are vulnerable).. fast forward 30 years, still too many vulnerable apps (we identified several hundreds) that are vulnerable.
since this is an issue of awareness, we thought it would be good to have a better name, just like "zip bomb" is well know, zip slip should be too. neither are zip only issues (others archivers and compressors are affected), but both make it simple to remember.
anyways.. looking back it's very easy to see the impact of such research, i'm not talking about snyk's marketing and such, i'm taking about hundreds of open source projects fixing the issue (maintainers confirming it), CVEs assigned, many developes learning about it (blog post, talks, etc).
peace