I don’t know how Johan got his numbers, but I do know that not every delighter is based on an idea from the idea forum. For example, if I look at the release notes of 7.13.0 (https://docs.mendix.com/releasenotes/studio-pro/7.13), I see many improvements which aim to delight our users. Seven of those have a link to the idea forum, but there are many more.
There is no separate list of delighters; the release notes are where you find all the improvements to Studio Pro (a.k.a. the Modeler in 2018).
Update: it could also be that our product managers have not marked all implemented ideas as implemented...