Hi community, i hope someone can help me with this,

We are migrating our e-commerce site next februari. I'm preparing the content migration. For a large part exact copies of our product listing and product detail pages will be migrated. 
However, we also have a lot of old blog content, which is, because of seasonality and trendiness, outdated and doesn't drive traffic anymore. It actually is just worthless content. (Not only as a traffic driver, this also counts for extremely low to none internal driven traffic (both internal search and internal navigation).

We have about 4.000+ blogs of which about 100 drive the most traffic (mostly incited by e-mail and social campaigns and internal navigation promoted on important category landing pages during some period.

Is it a bad signal to search engines to delete these old content pages? I.a.: going from a content-rich to a content-poor site?
Off course I will migrate the top 100 traffic earning content and provide proper redirects to them

Google's primary objective is to give users the best experience, off course they do so by crawling the entire web for the most relevant results based on their search queries.

Google's Search Console is a free service that provides you with links Google the came across / found in the before mentioned proces.

With this in mind, be aware that Google does not crawl the web to give you as a webmaster the most recent en relevant backlink reports.

many links in Google's Search Console can therefore be old, non-existing links (even in most recent link reports)
Another shortcoming of Search Console in my opinion, is that is show where links are/were FROM, but not where they link TO.

I personally think paid services such as MOZ, Majestic en Ahrefs do better jobs at this, because their primary objective is to give webmasters / SEM's the best experience, not searchers.